On the SDL, I haven't really had a problem. I can regulate the cabin temp with fan speed and vent positions. Haven't taken it on a long trip yet...first opportunity will be in August.

In fact, if it weren't for long trips, I think I really prefer the cold vent temp.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 160k miles
06 E320 CDI "Rutherford", Black on Tan, 180k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 79k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife