I have read that the oil temperature goes high when driving a 335i hard. Dinan offers a heavy duty oil cooler for $1400 (ouch!). The Dinan website also states that some 335i cars don't even come with an oil cooler. As I am about to order a 335i coupe with the M package: (1) Should this worry me if I leave the engine in stock condition? (2) If yes, can I order the car with a heavy duty BMW oil cooler? (somewhere I read that I could) (3) If I go with the Dinan oil cooler but otherwise leave the engine in stock condition will that invalidate my warrantee? (4) Anyone have an opinion regarding UPsolute upgrade vs. Dinan Stage 1 or 2?