I've had my E300 for a little more than 3 years and recently started to receive annoying phone calls telling me my warranty was going to expire. I started doing research and found that the choices were overwhelming.
Until finally found a company that was willing to give me a good product at a resonable price. That company was warranties 4 wheels, they answered all my questions and got me coverage for a price I could afford.

 

You might be able to get one through the dealer. I work at a retail store where if your item is still within our warranty or the manufacturer's warranty, you can still come back later and purchase the extended warranty.