I am new to this site. Purchased a 1999 Mercedes SLK 230 Kompressor 2 months ago. I drove a Mercedes C230 sedan until an accident. I know nothing about the car I have purchased, am the 3rd owner. Steering makes grunting sounds, and the keyless entry does not work. Also none of the buttons in the car function, like unlocking and locking the car, adjusting outside mirrors. Any hints available that do not translate to spending tons of money at the dealer? Purchased from a personal seller.