My wife wants to have the car parking sensor. To me it's a non-essential luxury. I had no idea it was standard among cars. But she says it's safer for the kids, and she keeps nagging me about it. She does have a point. But I would rather buy a rear camera, which apparently is about $1,000 in shops in HK, so no need for the parking sensor.
Anyway, if I have to pay $5,000 for sensor, camera, etc., so be it. But where can I find it?