Cabin Quality

If the cockpit in a Cadillac Escalade or Infiniti QX56 feels like a roomy lounge, the GL550's cabin is eminently more carlike. Don't expect massive armrests and a tall dashboard — rather, the wraparound dash and narrower seats could pass for those in a luxury sedan. The quality is good: Upper portions of the dashboard come wrapped in leather, and wood and chrome inlays effectively offset the lower panels. Nearly every surface is soft to the touch, including areas the driver's and front passenger's knees might knock against. Nice. Fit and finish is respectable, save for two unsightly gaps: one around the glove compartment, the other bordering the steering wheel hub.

The center controls look and feel high-quality, and it's nice to see Mercedes has stuck with black plastic where other carmakers have painted theirs tacky-looking silver. I'm not as keen on the navigation system. It uses Mercedes' Comand interface, which has proved handy in other Benzes I've driven, but this is an earlier generation with second-rate graphics, and it has to be used with tiny buttons alongside the screen. Good news: The 2009 GL-Class offers an updated system that doesn't use those buttons; I checked it out in an '09 GL320 Bluetec at an auto show, and it's a major improvement.

Blind-spot visibility is generally good, but most Cars.com staffers who drove the GL thought the tiny side mirrors were a joke.

    See also:

    Adjusting the exterior mirrors
    WARNING Exercise care when using the passenger-side exterior rear view mirror. The mirror surface is convex (outwardly curved surface for a wider field of view). Objects in mirror are close ...

    High outside temperatures
    If DEF heats up to over 122 °F (50 °C) for extended periods, e.g. as a result of direct sunlight on the DEF reservoir, DEF can decompose. Ammonia vapors develop as a result. WARNING When o ...

    DEF refill bottle
    DEF refill bottles can be obtained at many gas stations or at an authorized Mercedes-Benz Center. Refill bottles without a threaded cap do not provide overfill protection. DEF may leak if over ...