my prius "premium" in dash system can't run gps maps and fm radio at the same time or it crashes- had it back to toyota for numerous updates.
I learned hard not to put faith in a car builder who will put more $$ into marketing than technology
( the radio was mandatory cost to get the interior we wanted)
In my van I use a $40 wireless backup can from amazon- it works great past 4 years:
( right now it shows for a higher price- it regularly sells for 39.99, so wait)
my camera is mounted up by the 3rd brake light so that I have an angled view when backing to my gate