Well after reading priyas awesome project thread i feel a bit embarrassed to show my work, but I've been holding off for a while so here goes.
I got into a fender bender recently which required the drivers side front fender to need to be removed, so off came the fender flare, end cap, rocker cover and inner wheel well plastic, and what did i find?? You guessed it: rust and rot! so off came the rest of the plastic on the car and what did i find? you're right again even more rust and rot!! seems as though the plastic isn't really good for much other than holding moisture, dirt and road salt against old metal and covering the holes it creates. The plan is to repair all the metal and not put any of the plastic back on, instead i will uses a spray on truck bed liner around the wheel wells and along the bottom covering the replacement rockers. I will post picks as I go.
Driver side: about 50" of the inner and outer rocker panel starting at the front fender and going back is basically gone. there is a soft spot in drivers floor. the rear wheel well has two rotten spots 1 on the front near the back of the rocker and the other at about 2 o'clock where about 6 inches of the pinch seem is gone.
passenger side: about 16" of the outer rocker under the front door is flaky and soft, about 30" under the rear door is gone. the front fender has a big rot spot right at 12 o'clock. also front floor pan has a hole. the rear wheel well is in about the same shape as the drivers side, about 4 inches of the pinch seem is pretty rotted. there are a few other areas that will need some attention including the fuel tank hanger mounts and i am sure I'll find some more as i dismantel the vehicle. I don't have a big shop and lots of tools like some of you guys but i do have a small garage, mig welder, angle grinder as well as lots of other hand tools and some power tools.