We are the proud owners of two Smart Cars. We bought the wifes an line and got it in June of 2008. I bought a used one for me in 2010. the wifes car has 80,000 miles on it. Afew weeks ago the check engine light came on. pulled the codes (misfire #3 cyl.) Switched 1 and 3 plugs. Code returned. Switched coils. Code returned. Took the car to the MB dealer (since they now have Smart) $125 just to plug it in. They said it has low compression in #3. Could be burnt valves or bad rings. To fix it they have to pull the motor so they can remove the head. I ok'ed the repair. they next tell me that #3 injector is bad and that the valves can not tb lapped in because the valve guides are worn too bad. The cost to remove engine and replace it was quoted as $1500. With the assorted new parts and machine work to fix the head the repair cost is now up to $3500. Now they tell me they can not find replacement valve guides. A new head will add another $1500 to the bill. They found a machine shop that will make valve guides for $400. I told them that I will make the new guides and take them to the shop doing the work.( I have been a machinist for 40 years.) I go to the shop to take measurements for the guides and learn that all six of the exahust valves are worn beyond repair. SOOOOO .... After this long discription of my problem, here is my question. Has anyone else had this problem with their car or did I get the first lemon from Smart. I am having a tought time understanding how a motor with only 80,000 miles can have all six exahust guides wear out at the same time. I have had many other cars with 300,000 pluse miles on them and never replaced valve guides. Any suggustions, advice, or general thoughts would be helpfull. I feel that even tho the car is out of warrenty, I should get help from MB because this is a design defect with the motor.