Well I took my 1992 BMW 325i to get the A/C fixed the other day. Dropped the car off in the morning and they had it done before I got home from school! Awesome service. Anyway, they upgraded the system from R12 to R134a. I would have liked to keep the R12 but they didn't stock it and said it would be hard to get so I got the conversion. Well it only took a few hours and $150 and they put int he R134 and dyed it so we can find out where the leak is. I've heard people say the air conditioner wasn't as cold after switching to R134 but mine was ice cold when I got it back and so far I'm very happy with it. I got it done just in time too, it's starting to get hot in NJ.