Come on Bocabenz, you know you'd love to show off your exhaust (single or double) if you could! (LOL)
ps. I do agree though that the spare tire inside the SUV, taking up much needed cargo space, is unfortunate - But damn, my ML's backside looks GOOD!
I am a minimalist and love symmetry... On the simple rear bumper of the 2000 ML's, I wouldn't want a single tip spoiling the simplicity, thus the reason I don't have a chrome tip. However, if I get an ML550, I guarantee it will have quads.
__________________ 2000 ML430
K&N air filter - Ate brakes - chrome grille, tailgate latch, logo on rims, instrument cluster rings - projector style lights w/xenon bulbs - white LED lights on licence plate - handpainted pinstripe - designo Java Shift Surround
Mostly aesthetic. If you examine most factory model changes that add dual exhaust you'll find the actual throughput of the system does not have a material change. There is usually a constriction added in the chain or it is not a true dual system but merely a cat- or exhaust-back dual.
Making any change to a modern stock vehicle results in some negative effects. In the case of exhaust systems when you open it up you are modifying the power curve. It does _NOT_ result in an across-the-board increase in power. What it does it drop the power, often dramatically, in the lower RPMs while increasing the power slightly in the higher RPMs.
Now, if you spend all of your time with the engine higher than 4,000 RPMs then you'll see a power increase. But since nobody does that in normal driving what 99.99% of the population will see is an actual decrease in power. But it will sound louder, they'll think it will look better, and they'll never want to admit that they got ripped off <g>.
Don't forget that twice as much pipe will weigh more=less power and less gas milage. I think that every 100 pounds of extra weight reduces the milage by 1mpg.