Websites that won't allow backwards navigation. Let me explain:
You are search for a widget, but don't know the classification. So instead of starting at the beginning and branching ou to the product you use the search function, and find one such eaxample of a widget. But from the product page, you can't click on the category/subcategory to look at similar items. Like the tree should look like "Toyota - 2010 - power train - fuel delivery". Such that I could click on fuel delivery and see other related parts.
Also, websites where adding more terms to the string broadens the search rather than narrowing. Like searching for "2010 Toyota Corolla gas tank" returns every Toyota part, every tank (regardless of make), everything related to gas, plus every 2010 part in the inventory. WTF is the use?
You could try searching for "Fuel tank" instead!
I do feel your pain, though, I tried to find a 100nF Mylar capacitor (Yaesu specified them for an AF filter in one of their radios.) on Jaycar's website.
On the first try, it hit me with every 100nF cap they had in stock, plus some other values.
OK, I will just search fot "Mylar capacitors".
This got me all those, plus a whole lot of other things, either made of that material, or having a name a "bit like" that word.
So I Googled, & found that Mylar, which I had known as sheets of insulating material used in various applications at my old jobs, is the same stuff used in "common or garden" Polyester caps, so all is good!