Exceeding GVWR probably would work out 99% of the time, sure, but if you get pulled over by a knowledgable cop or, worse, get in an accident and your insurance company discovers out you (and your vehicle, too! <cue rimshot>) were overweight then it could be much worse, no?
About the worst case that could happen is illustrated in this possibly apocryphal thread: http://www.glamisdunes.com/invision/...howtopic=24262
Well, after almost a year has passed since my buddy lost control of his FS3000 toy hauler being pulled by his F-250 coming down Sierra pass. He had sway bars and bags. The trailer swayed somehow and took over the control of his tow rig. He ended up smashing into another vehicle and the passenger in the other was killed and the driver injured.
The highway patrol cited him for hauling the trailer with a tow vehicle that was not rated for the weights of the trailer even though he was not too loaded up. The injured sued him big time, the insurance company disowned him due to the fact that he was improperly rigged and was "using his vehicle for purposes not intended by the manufacturer" even though they insured both vehicles.
He is awaiting trial for manslaughter, lost a civil suit for 1.2 million dollars, of which he was able to get 300,000 dollars from his insurances company sold his home, toys and vacation property to pay for it.
His wife divorced him and he is probably going to do some time.
Bottom line is the man is broke, lost his wife, affected PERMANENTLY the life of another man, and killed a woman all because he didn't want to spend another few grand for the right sized tow vehicle.
Moral of this lesson: BE WARNED! You idiots out there that know you are over limits or running too small size tow rigs, PRAY you never get in an accident!