The parking sensors on my wife's August 2015 sometimes react to heavy rain, trouble seems to be that the current range of PDC systems are enabled at all times but should not react to anything is the car is travelling above a certain speed, gets a bit disconcerting at times.
Wading, when I had a VX Cav GSI 2000 4x4 saloon, there was an extreme down pour of rain round about a busy commuting time of day, the local police forced all of us on to the opposite carriage way and half on verve and half on road through extremely deep water, I did not feel too good about having to comply, a few years later the Cat started to rattle, it having a ceramic core probably suffered thermal shock that day - but what can you do? I seem to remember that that day's commute was about 4 hours instead of 30 minutes for a 10 mile run, grid lock every where.