New to MB and have a few Q's!
Physically, the car hasn't changed shape or dimensions much at all. Best value would, in my opinion, a '08 320 CDI (no run flats, better fuel economy, the resale value of a diesel, etc) IF you can find one.
Do not have high expectations for the performance of the Nav system.
Decide what color/features you and your wife want, prioritize those criteria, then shop hard for a pre owned car that comes closest. Be prepared to go quite a distance to get it (one that matches most of your criteria).
Persevere!
whatever year you choose, you should be happy with the gl.
10-New Lower Front and Rear Bumpers, New Fog lights or optional DRL LEDs, New 20" Wheels Std on Diesel, optional on 450, Minor change to Speedo, Tach appearance, Tire Pressure Monitor gives specific pressure display for each tire, LED tail lights
11-New Mirrors (2nd Change), Blind Spot Assist available, Larger Rear Headrests
There are probably a few other minor changes or options available on newer models. Unless you've shopped for a GL or owned one you probably wouldn't be able to tell the differences between the years. I don't think there have been any "sheet metal" changes, just bumper and lighting changes. The premium packages change significantly from year to year so don't assume that because a 2009 has certain options included on a given package that the '10, '08, or 11 will have the same options.



