Painting /Dying the interior
the rear seat won't hold up to anyone sitting in it if dyed, i've used the part store stuff and it looked fine
Not true! I dyed the entire interior including the seats of my Barracuda from medium blue to black with SEM vinyl dye and the seats held up fine. The only area that ever showed any signs of wear was the piping on the edge of the seat where I slide my fat butt in an out. In that area I just touched it up once or twice per year.
When the stitching in the front seat started to tear a friend gave me another with perfect white upholstery and I dyed it black and used it for several years until it tore at which time I had the funds for new seat covers.
I have tried both SEM and Duplicolor vinyl dyes and find the SEM Landua Black to look much more natural than the Duplicolor black.
The key is to clean, clean, clean, then clean some more. I used an ammonia based household cleaner after which I used SEM vinyl prep before appling the dye. Any signs of fish eying means you didn't clean enough.
BTW, I did my interior (except for the carpet and headliner) in 2000 and the door panels, visors, dash pad and plastic trim pieces are still the same pieces I dyed and I have put 66,000 miles on the car in that time frame.