I think OPs issue is he can't find the frame rails due to all the plastic cladding. I have a similar problem with my current-gen Prii. There's about a 3/8" gap in the plastic that lets me eyeball the "frame rail" parts of the floor pan and then I have to count on my depth perception to set the quik-jack up correctly.
Ah. Reading > Me. Our 7th gen Camry has a metric shi*onne of that plastic cladding as well. Does make it hard to judge.