Hi to all!

I heard that all W211's prior to '08 are unreliable. They break down a lot. How true is this?
I am now having a second thought if I will buy this 2007 E350 4Matic with a 25,000 miles on it to a non MB dealer.
I never had a problem with my 2000 E320 not until last week when somebody rear ended me and shoved me to the car in front of me. It was totaled! I put 109,000 miles on this car and never had a major problem.
I am also considering a 2002 E430 4Matic with 36,500 miles on it. I saw the car yesterday and hasn't been detailed yet, it looks good to me but when you open the driver's side door you will feel and hear 2 stages of loud clicks before it fully opens, but it was smooth when you close the door. The Exotic car dealership asking price is 17K. Is the car worthy for this price?
Just in case I will buy the W210 what kind of maintenance that I need to do right away before using it? Will there be any major problem in the near future?
Please I need a feedback to all MB experts out there!
Thank you so much!