I have a 2005 audi A6. I just bought it from a dealership and drove it home. I was on my way home from work the other day and it started to not engage untill the rpms were over 2.5. and it didnt really want to hold a steady speed. I tryed to put on cruise control till i got home but it kept just shutting the cruise control off. Then i tryed to started it up the next day. and it didnt want to turn over at all. I just kept hearing a click click click.

 

Have the dealer pick it up and diagnose it. From your description, it could just about be anything from relatively minor to super serious. The failure to turn over and clicking sounds like a failed battery to me.

 

Thanks for the input! wasnt sure any body would even respond