I was wondering what would happen if I some how could put R-134a (the cheap, new ac stuff) into my 82 300D. Ive been told by a few mechanics that if I could get a way to change the valve to accept the new stuff, I would be all set for working a/c. The only reason I ask this is because I have a serious leak in my ac system and I am too cheap to either fix it or keep on dumping R-12 in. (Even with a licence to buy it, R-12 still costs 35 bucks a pound) Is there any damage that would occur to my system if I tried something like that?<br> <br> My second question is that ive got a 20 year old driver side seat that is really starting to sag, and make strange noises when I sit in it. These seats are usually very comfratable but this one is just too old to be comfratable. Any of you guys have any cheap ideas that I could do (without buying new springs) to add a little more firmness to the seat. I was thinking of bolting plywood to the bottom of the springs, but I want a few other opinions before I do anything. Thanks!