Buying a Benz from an Infiniti dealer?

[C280 Sport]

Input needed here. My son came across as wonderful looking 2004 C240 4MATIC.(Car has just 45,000 miles). Has power everything, lather, navigation, heated seats, sunshade and the duel zone climate control and some park system thing.. The one thing is that it is at an Infiniti dealer. We called up in it and I told the manager I won buy unless I get a pre purchase inspection. He said its fine and he would let me take it to my independent shop that I use. This car looks clean as can be. So the question here. Do I get the prepurchase inspection and buy this car? Or wait and keep looking around for another C240 or C320? I have just never felt comfortable buying a car from a dealer who doesnt specialize in that car.