The standard of driving in California is awful - from memory of the UK you have it easy! After a couple of near misses when other drivers ran through red lights and stop signs I brought and installed a dash cam in our Mustang.
Well long story shot we used a valet service at a San Fransisco hotel during our Christmas trip. On the 3rd day when we collected the car the driver’s seat had been heavily adjusted and the fuel gauge was lover than I remembered.
So I check the tracking system to find that on the 2 previous days the valet had taken the car for a drive around the city for over 1 1/2 hours in total! And the dash cam recorded it all, along with GPS position and the idiot moaning about the fact the car is warning them of traffic cameras and keeps beeping (the g shock saving the videos). Cost the hotel about $1500 in repairs and compensation.
More than paid for itself 
W.