The big problem with the JLR thefts is the vehicles are becoming uneconomical to insure, or are completely uninsurable in some cases - I've seen £10,000 per year quoted for some Evoque models, and other insurers outright refusing to quote as they don't like the risk.
The only way JLR can reasonably fix this is by recalling the vehicles and loading improved software on them; they've announced an update for 2018 models onwards, but it seems earlier model owners are screwed. Funny that UK law has a cut-off of six years to bring a claim for a product being unfit for purpose, I'm sure that had nothing at all to do with their decision to exclude earlier models.
There is no good fix to the repeater problem besides using reliable ToF measurement. If the radio chipsets don't have ToF support then they are screwed in terms of a true solution to relay attacks, but they could still prevent CANbus/OBD-II attacks, and/or offer a feature like PIN-to-drive for free.