I've spent around $2k getting my 300E just how I like it. Nothing that it didn't need, just things to make it safer and more reliable. Most were usual parts that a 12 y/o car would need, just happened to be in the first 6 months of ownership.
My $7000 total investment feels, looks and drives a whole lot better than any $7000 saturn or similar, just happens to have 200,000 more miles on it. As a rather attractive young lady who I gave a lift to from a party the other night commented on sitting in the car: "mmm, this is nice", I knew my work and money was well spent
(unfortunately, her husband was sitting in the back...hehe)