detecting that a vehicle has been touched.

[coromonadalix]

there was some alarm systems in canada like this. but the biggest problem was sensitivity, they started for almost nothing and everything, rain  wind   anything  touching the car,   nearby vehicule(s) making dust  etc ...

not to be confused with movement detectors, witch too was a pain in the @#$@

in the end it annoy everyone around your car,  i myself don't react to this anymore,  get yourself cameras  or find a closed garage    sorry

oil plug could be your last car service done by a goon ...   happened to me  the plug came off by hand, i was mad

for anything else in the tire could be simply hazard,  i had a 1/2 drill bit in my tire once ...  how ?? absolutely dont know

not bashing on your problems  BUT  keep in my the neighbours who can complain ... and give you more problems

[KE5FX]

Flowing my previous topic about people meddling with my car and wanting a deterrent I am still suspicious, Changed the oil today and the sump plug was loose if not part undone, never happened before.

Dude, nobody is messing with your oil drain plug.  Check for a CO leak.

If that's not the problem, find another oil-change place where they know what they're doing.

[coppice]

Flowing my previous topic about people meddling with my car and wanting a deterrent I am still suspicious, Changed the oil today and the sump plug was loose if not part undone, never happened before.

Dude, nobody is messing with your oil drain plug.  Check for a CO leak.

If that's not the problem, find another oil-change place where they know what they're doing.

Why do you think that? Nails wedged against tyres, so they puncture as you move off, loosening of key accessible parts like a drain plug, etc. are the classic activities of UK yobs.

[KE5FX]

Why do you think that? Nails wedged against tyres, so they puncture as you move off, loosening of key accessible parts like a drain plug, etc. are the classic activities of UK yobs.

He said he found a nail in his tire, not that someone had propped one up.  If I suspected foul play every time I had to patch a tire, I'd never leave the house.

Around here, if someone has access to your car's undercarriage, they won't screw with the drain plug, they'll Sawzall your cat.  Maybe our prestoopniks are just more profit-oriented...

[johansen]

High voltage generator and a wire dangling off of it to charge your car up to 20kv or so.

When they get zapped just claim your special tires self generate static electricity

[Rick Law]

I've been using PIR (via Arduino NANO) to trigger exterior lights, an alarm, and to trigger photo saving on an exterior pointing camera that snap still shots every 4 seconds, normally discarded unless PIR is triggered.  It work very well with cats up to 15-20 feet for over a decade.  But you are dealing with something a lot heavier than just "is it a cat or what?"

If someone is sabotaging your car such as messing with your pump or nails near the tires, the best way to handle that is calling the police.  That leads to evidence: the best is probably video.  Imagine trying to explain your PIR or Sonic distance sensor log to the police, or to jurors in court...

Video will also show you directly whether it is a cat, someone walking the dog, or even perhaps a rat visiting your car to chew on the tasty wire insulation.  With a video of what is visiting, you can choose the best next-step.

Avoid any drastic.  You could be held liable to the damage it did to the saboteur.  "I was just walking pass the looking for my dog and I got knock to the ground...  Now my teeth is broken and I want to press charges...",  worst yet, "Sir, you are under arrest for manslaughter  -- John Doe slumping over your car is dead with a heart attack after your car gave him an electrical shock... he told his wife, now his widow, he was merely out to look for the dog..."

This is a real case:

A 77-year-old man has been charged with manslaughter in the death of a neighbor who died when she tried to free one of her pet dogs from the man's electrified fence. The police said James J. Kahl had failed to install a regulator that would have sent a pulsating current through the wire instead of a steady flow of 110 volts that killed his neighbor, Bertha A. Brittingham, 73, on Tuesday. He is free on his own recognizance pending a court hearing.
https://www.nytimes.com/1988/05/16/us/electric-fence-kills-woman.html

[coppice]

Why do you think that? Nails wedged against tyres, so they puncture as you move off, loosening of key accessible parts like a drain plug, etc. are the classic activities of UK yobs.

He said he found a nail in his tire, not that someone had propped one up.  If I suspected foul play every time I had to patch a tire, I'd never leave the house.

Around here, if someone has access to your car's undercarriage, they won't screw with the drain plug, they'll Sawzall your cat.  Maybe our prestoopniks are just more profit-oriented...

In the UK a lot of punctures are due to this kind of vandalism. The use of a sawzall for car attacks is usually limited to removing the catalytic converter, so its more commercially oriented vandalism.

[MrAl]

Flowing my previous topic about people meddling with my car and wanting a deterrent I am still suspicious, Changed the oil today and the sump plug was loose if not part undone, never happened before. I also have a nail in the back tire on the offending side of the car the MOT test told me. So plan is that I'll set up a light in the car so that anyone touching it will set it off.

I can preferably use some sort of touch sense or have to resort to pir sensors.

Anyone any idea on how to achieve the touch method ? I assume that it's a capacitive measurement ? Once again the problem of needing to use the physical ground as "earth" for sensing a common side for vehicle and "toucher" (scumbag)

Hi,

I would go with the camera setup, either infra red or even visible light, if you have the car in such a position where you have a good place to mount the camera.  The actual security cams are much better than web cams because web cams stop working sometimes for almost no reason.  If not anything else though a web cam will work for a while and maybe if you get a good one it will work all the time, but you'll also need a dedicated computer for that running 24/7.  The security cams of today have exceptional detail too, and can detect motion, or you can just let it run constantly and only check it if you see something has been tampered with.

If nothing else, perhaps a light in the car can come on randomly and that way they will never know when it might turn on again.

I've had my fair share of this kind of thing so I know exactly where you are coming from.
An extreme example was one of my front side lights was replaced with a different color lens.  No kidding.  The car had orange side lights on both sides, then one day it had orange on one side and clear on the other side, and I have before and after photographs to prove it.  That was just nuts.  It may have been one of the garages that it was serviced in, but they never said a word.

They also have cameras now that can work in very low light so you may not even need an IR illuminator with that kind.  The regular security lights come with a set of IR LED's mounted right on the front of the camera so you don't have to get a separate IR source.
The security systems are exceptional too. They store the video on a hard drive.  They have all kinds of alarms too even audio as well as visual.  if something is detected, the video starts recording onto the hard drive.  A 1TB hard drive lasts a long time too, several months, and then you can just record over it when nothing has gone wrong with the car.

The best bet is to go covert on this though so you can catch who is doing this and have evidence on hard drive or tape.  A hidden camera is best so they do not know the car is being monitored all the time.  If they find out it is being monitored, they may find another way to cause damage, and it would become that much harder to stop them in the future.

What else would be cool to set up would be a dummy camera pointed in the wrong direction while the hidden camera catches everything.  For example, one of those rotating cameras that rotate back and forth maybe 180 degrees.  When it happens to point in the other direction, they may be tempted to try to fool the camera, thus getting caught red handed.  This should probably be a last resort though because it may just scare them into doing something else.

One of my neighbors got their wallet stolen out of the car in the driveway.  Why they left it in there I have no idea.
Another neighbor had someone scratch the whole side of his car with probably a key.  Right down the whole length of the car.  That's nasty.

Good luck.

[radiolistener]

Flowing my previous topic about people meddling with my car and wanting a deterrent I am still suspicious, Changed the oil today and the sump plug was loose if not part undone, never happened before. I also have a nail in the back tire on the offending side of the car the MOT test told me. So plan is that I'll set up a light in the car so that anyone touching it will set it off.

It won't help. If they want to stole something from your car, or your car, it will take for about 5-10 seconds and light, loud alarm or camera cannot stop it.

But if you want to scare off the neighbor's cat that plans to nap on your car's hood, a loud siren will do just fine.

It will be more difficult with dogs that want to pee on your car's wheel, as a shock sensor won't help here. You'll need a capacitive sensor, which will frequently trigger false alarms.

But all these loud car's alarms are quite annoying. For example, here they constantly triggering during the city's bomb shelling, and their wailing makes it hard to sleep at night...