I have the R-12 topped off in my '85 SD and it can get darn cold in there on a hot California day. When you test your car, check the sight glass to make sure there are no bubbles. If there are, get a leak test done by a competent a/c house and have the owner fix the problem - which can run very high $ if you have to replace components. Thre is no real difference in temperature for the driver in a sedan vs a wagon, although that will not be true for passengers, especially those way back in the 3rd seat.

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'76 240D-Sold
'78 240D-Sold
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet- under restoration
'86 560SL 124K Miles-Sold
'94 320E Wagon, 74K Miles-128K Miles JUNKED
'06 E350 Wagon, 84K Miles
07 SL550, 14K Miles