I posted this on another forum but please be aware that the latest RX450h models (mine was 2018 Sport CVT) have a massive vulnerability. They can be stolen in under 45secs, they stole mine in 44!
This is not a relay theft but known (as I discovered after the event) as CAN BUS theft. Basically the thieves punch a hole above your front left wheel arch to access a cable that connects the the headlight to the controlling computer, connect their own computer and start the car. Mine was stolen at 8.43pm on a weekday night in a residential street, took 44secs from approaching the car to driving off. My keys were over 100m from the theft in a Faraday pouch and I had CCTV, unfortunately not clear enough to see their faces, showing what they were doing.
Lexus know about this vulnerability but neither tell customers or recall the cars to fix the problem (as the latter would create a liabliity and allow customers like me to recover thier loss ie excess on insurance etc). For example if you insure your RX through Lexus they offer a second immobiliser to counter this vulnerablity (albeit your car will have a hole in the front wheel arch). But in the UK as a customer your 'contract' is with the seller of the car, even if it is a main dealer, not the manufacturer unless they recall. This was confirmed by the team at Which Legal who said unless the dealer has deliberately misled you about this vulnerability then you have no potential case to recover your loss.
Currently a steering wheel lock may deter the thieves (as if it is a good one will add a couple of minutes to the theft), a second immobilser will mean you dont lose the car but it will still be damaged. But the police confirmed that most of the London thefts are a professional gang, any car stolen is highly unlikely to be recovered and that 'a lot' of Lexus RX and UX are being stolen up to 10 in one night.