Well, first let it be known that I had the M3 for 4 years, and 36,000 miles. I got rid of it because it was coming out of warranty and frankly I had to many bad experiences with the local dealer when it was under warranty and god knows what it would have been like after the fact. Originally I was going to wait until the new M3 Hartop Convertible came out, so I leased an Acura TL to use as a daily driver (damn fine car by the way). One day a few weeks ago, I had a few hours to kill between appointments and was driving by the new Mercedes dealer here in my town, so I decided to stop in. Sitting out front under the front porch was this bright red SLK. I thought for sure that it was likely a 280 with a body kit or something, then saw that it was a 55, then I realized it was an 06 leftover. So I took it for a spin, had my wife come out and drive it with me, and then decided that I would never drive it and that it was too impractical. That and the fact that my initial impression was that the dealer would not negotiate too much (my bad, in my mind I was thinking that this was the other Mercedes dealer in my town which I do not care for.) So I left, stopped by a week later and saw that they had a price reduction sign in the window. A couple of days later I was in Columbia SC and had an hour os so to kill, so I stopped off at the dealer down there. I took an 07 for a spin, and on the way home called the wife to say I wanted the car and that if the dealer would take my offer I was buying the car. Well, what I thought was an offer they would flat out refuse turned out to be only about $500 off where I bought the car.
So I have had it since Wednesday, and I must say that my initial impressions are that it is a vastly superior car to my old 2003 M3 convertible. First, it has a V8, that has all kinds of torque and is one of the best sounding exhausts I have heard. Second, the 7 speed auto is great, I had the SMG in my M3 and although I really thought I wanted a manual shift in my next car, I realize it is not needed with the AMG engine. I love the transmission! The SLK is a much tighter feeling car, then again it is much smaller. However, it rides better than the M3. I still think my old M3 may be better looking (I just liked the way e46s looked and it was an exclusive M color in Carbon Black), and the back seat was nice to have. However, the SLK feels more like a sports car, drives more like one and frankly although I know it is a tad faster than the M3, it feels a whole lot faster, which frankly to me is more important (when I say feels faster, I mean in terms of acceleration.)
The M3s handling was a little more predictable, mostly I imagine because of the longer wheelbase, but in time I am sure I will adjust to the SLK. I drove a Cayman S and Boxster S in recent weeks as well. For the record, these two cars will no doubt at the limit out handle the SLK, however in the real world I prefer the way the SLK rides and handles to the Porsches and with the top up it feels as tight as the Cayman and with the top down, it feels more open than the Boxster with its top down.
Do I love my new SLK 55, well hell yes. Do I miss the M3, not really which surprises me, but that is how much I like the SLK.
Hope this answers some questions. I will post some pics later once I get some taken
By the way, the air scarf should be mandatory equipment on all convertibles, it is awesome!