Getting sued after selling car. What to do?

[Iksur]

So I sold my car on june 8 2013, the car had a rebuilt title and was obviously used. The buyers inspected the car, they test drove it, and liked the car. I did tell them that the engine was overheated from the previous owner that I bought it from, did not tell them why or how it got overheated since I really don't know the full story of it also. But that should not matter since I put in over a years worth of time to fix this car into good workign shape, I bought all parts from the dealer, and looked up on smart fourms to get everything fixed correctly. After I fixed the car, I drove it for over a year, and then my wife just told me that we need a different car, so thats why we put it up to sell it.

So after selling it, we get a call 3 hours later that theres some "oil" light on, I told them that it was just to remind them to change the oil, as the smart cars have the light come on every 10,000 miles so the driver does not forget to change the oil. They did not reply after that so I figured that they changed the oil and everything was fine. On the 11th I checked that they registered the car to their name, so everything was okay. Then 2 days after than june 13, they text me saying that the wife overheated the engine, and the thing is with smart cars you need to know how to drive them, you cannot give to much gas etc, and i did tell them this when they were buying it.

After the text message, I told them that I was sorry that , that happened, but they did inspect the car, and test drove it, I don't know why they overheated it, since I fully fixed everything, and that I could not do anything about it since it was their car. After this they tell me that they took it to the dealer and that it will cost 5,000$ to fix.

After those texts, I did not hear from them again for 4 months, so I thought that the problem was fixed and forgot about the car. But about 5 days ago, I had the couple come up to my , shove the papers to me, and walked off and drove off.

I realized I was being sued for $5000 dollars and their claim was this.. " Defendant negligently misrepresented the used smart 2008 vehicle that was sold to the plaintiffs" I litterally have no clue how I misrepresented the car.. I told them everything that I knew about the car, all the oil changed etc.

Please help me with what I should say at court since this is the first time I've ever been sued for anything, in my whole life time. No lawyers want to go on a small claim so I am all on my own.