I bought my '99 SLK230 new.
It is the base model and my favorite commuting car.
I now have over 110K on it and it has been a very good car.
I have had what seems to be pattern failures on the vehicle.
MAF sensor right around 70K miles, K40 Relay failed at 78K and I found and re-soldered the melted connection and it has been good ever since. one could simply buy a new one, for under $100 and replace it quite easily.
I did encounter a noisy camshaft variable timing unit which was the most expensive part I've replaced, part cost was close to $400. and I'm a Euro car tech so fixed it myself.
The electrical connector on the transmissions leak fluid about every 5 year/50K miles.
I've replaced one plastic shift bushing and think the second one is now due, the parts cost is about $1.00. They are a little tricky to replace but can be done even without a special tool with a little patience, but the special tool is great.
Even though I have other MB's to drive, such as a CLK cabriolet, if I am running errands and such this is my "go to" car. It is just fun to drive. They are a bit noisy or more so than most MB's so I think they got a bad rap early on, as I recall many being for sale shortly after being purchased with very low miles many years ago. One thing that contributes to higher noise levels in this vehicle is when the rear tires get some miles on them. One might think there is a problem with the rear differential, the noise is so pronounced. With the staggered tire sizes on this vehicle, rotating front to back is not an option, so the tires do acquire some pattern wear. This is exacerbated if one purchases cheaper tires with a large block tread, so beware.
As far as mileage goes, in normal commuting, I conservatively get 24.5 mpg and have achieved 28 mpg on long highway trips with the A/C off and 70-80mph cruising speeds. Short drives of 2-3 miles with lots of starts might drop the mileage down to 22.5 or so, but this is rather unusual.
The color of my car is white and it still looks fantastic after all these years. I have used the factory touch-up paint to fill in some paint chips and the car polishes out very nicely. Recently, we drive the vehicle down to vote and was stopped by some admirers who thought the car was new. Clearly not an MB person, but reflects positively on the condition and the enduring style of this original SLK.
I bought my 1999 SLK used in September 2008 with only 25,000 miles on the odometer, which is very low miles for a 9 year old car. This model has a timeless style that still looks new....everyone who see's it cannot believe its not just a couple years old instead of 9. It's definitely an attention getter, mine is black on black. I now have 38,000 miles on it and all I've had maintenance wise is oil changes and tires. At 52, I plan on this being the last car I own, I'd never get rid of it!
This car is great. After I bought this car, I looked at many reviews on the SLK and it got a lot of scorn and bad reviews about bad handling and mediocre performance ect. But the SLK230 is honestly a fantastic car to own. I have the one with the sport AMG package which adds the AMG body kit and wheels, but not a suspension upgrade as I assumed until I looked it up. This car is built solidly, when Mercedes was good and not overly complicated with computers, and for that reason I believe its so reliable. The reliability for me could rival a Toyota, no problems at all. The handling is excellent. It stays flat in the corners and is extremely nimble with good steering feel.
Cool car, but the top can be very troublesome (and expensive to fix).
If you are considering buying, make sure top is in good working order.
Fun to drive, but 4 cylinder is a little weak and doesn't sound great.
Bose stereo is terrific.
Ride is harsh, but to be expected.
No mechanical problems in the 10k miles I've had the car (90k-100k),
Also, be careful you don't close the top on something rigid - you will shatter the rear window glass.
Ask me how I know.
I puechased my pre-owned 1999 SLK230 in 2008, for $9995. It had 115,000 miles on the odometer. The near flawless exterior burgundy paint finish, and the excellent unretouched condition of the interior hinted that this car had not been abused. The SLK230 looks best when viewed from a 3/4 view at the rear. It is definitely sexy, and draws a lot of attention when being driven. This car is best put through its sportscar paces when driven by an experienced driver who knows how to shift the 4-speed automatic tranny manually. Downshift to 3rd when entering a curve, and then floor it at the apex of the curve. It will rocket out of the curve as if on rails. And still give 25-30MPG. Wow