Just my personal opinion, but that thing is kinda hideous.
First, with the bed being that short, it makes it look unproportioned (sp?)
Next, the over fenders don't really look like fenders, but very large flares. The rear fenders should be larger, which gives the dually its oversized stance/look in the first place. Those flares takes the look of a dually, and the body line, out of it.
Then there is the badging, which has been mentioned a few times already.
I would really love to own a MegaCab, and I think that a nice lift and larger tires helps even out the look of the MegaCab. But the shortbox, those funky fenders, and just the overall look of the MegaCab Dually, will stop me from buying one. If they came with the 02-05 rear fenders, now that would be a nice truck.
Again, just my personal opinion, so please don't flame me for hating it...
