CLK320 is a mushy slow 4 seater that feels cheap despite not being cheap. The only thing going for it is that it is branded a Mercedes. Want a more competent convertible for four at the same price ? Try the Saab Linear or the BMW 330Ci.
The car does seat four people [really tight fit for the ones at the back]. and Id call it a 2+2 rather than a 4 seater. Personally, I prefer 2 seater sports cars - with the Porsche 911 being the lone exception to my rule - in which I deem a 2+2 OK - or in the Porkers case, an awesome car to drive/own.
The slushbox [auto tranny] stinks, and unless you move up to the AMG version, the car is woefully underpowered.THe car does come standard with a decent stereo with 8 speakers, ABS.
Stock wheels are OK, and while Mercedes nickel-dimes you for options, they are nowhere as bad as Porsche.
Bottom-line: This car is for people who want a Mercedes, and NEED to carry more than two people. There are much better, more competent and nicer looking cars that are drivers cars at the same price point.