Are the R134 A/C systems as big a POS as the R12 Freon versions? What year did the switchover take place? (1994 and up?) Are evaporator leaks still a problem on the 134 gassed verisons? Any other things to look for in a 134, (factory, not converted) How, if at all, did the W124 A/C sytem evolve given the early problems they had........Thanks Clip BTW Looking at a 94 E320 Coupe.........