2007 SLK350: ok for cross-country?

EDIT:
(Note to admin/mod: I just re-posted this in the General thread, as I realized that I actually want feedback from the entire community here, since I'm asking for suggestions of alternate vehicles. Feel free delete this R171-specific thread, thanks!)

Hi all,

I'm planning to go on a road trip across the US and back, within a 3-week period in May 2014.

Details of the trip are here:
http://WakeUpAndCode.com/road-trip/

Given the long distance of the trip, do you personally think it would be a good decision to take my 2007 SLK350 on this road trip? I bought it brand new in late 2006, and it has around 55k miles on it, as of late 2013 (that's 7 years).

I haven't had any major issues with the car that couldn't be fixed, and it has had all its recommended services.

Thanks in advance!

Shahed C