I'll second what Kent said. There are transmission issues from 97 to early 99. You'd avoid that possibility with the 2000. I'm also a little biased towards a 2000 E320 4Matic Wagon since I've got one. There isn't any situation I've been in with that car where I've said "I need more power" and wished I had a V8.

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Jonathan

2011 Mazda2
2000 E320 4Matic Wagon
1994 C280 (retired)