Thinking about buying an E430 4MATIC

[ss109]

Alright, I have done my research, looked at several cars, and have narrowed it down to the E430 4MATIC and the 540i AWD. Being that my first car was a MB, and my second is also one, I think I may have to stick with the MBs =) Anyway, the one thing that is pulling me away from the 4MATIC is the fact that I cannot get the AMG sport styling package with it. I was thinking about getting a 4MATIC, and then getting the sport package put on at a later date; would this be impractical? How much would I be looking at spending? Antoher queestion: what kind of "real-world" performance would I expect to see in this car?

Thx