Here's my understanding:
Doors/Mirrors:
Vehicles that were produced with the intent of having user-removable doors are legal. However, a side mirror on the driver's side is required (mirror relocation brackets).
http://www.rockymountainextreme.com/showthread.php?t=14458&highlight=mirror
First time I removed the doors on my YJ, I was pulled over by an SLC officer. The officer was nice (no ticket or harassment) and just told me I needed to mount some kind of mirror on the driver's side.
Flares/Flaps:
According to Utah code, if the track width of a vehicle is increased, then the fender or fender flare must cover the full width of the tire. I took the definition of track extension to include wider axles, wider wheels, offset wheels, wider tires, etc. It appears that if you run stock width track, the tires can extend beyond the flare/fender, but only to the degree that it was originally from the factory. So, if your stock vehicle's tires stuck out slightly, then that was okay, but if you modify the track width, then you must completely cover the tires.
From House Bill 49 "Vehicle Suspension Lift Laws" State of Utah:
"2) If the wheel track is increased beyond the O.E.M. specification, the top 50% of the tires shall be covered by the original fenders, by rubber, or other flexible fender extenders under any loading condition."
Mud flaps must cover the full width of the tire and at least 50% (radius) of the tire's height.
From HB49:
"(b) The wheel covers, mudguards, flaps, or splash aprons shall:
(i) be at least as wide as the tires they are protecting;
(ii) be directly in line with the tires; and
(iii) have a ground clearance of not more than 50% of the diameter of a rear-axle wheel, under any
conditions of loading of the motor vehicle.
(3) Wheel covers, mudguards, flaps, or splash aprons are not required if the motor vehicle, trailer,
or semitrailer is designed and constructed so that the requirements of Subsection (1) are accomplished by
means of fenders, body construction, or other means of enclosure."
I currently run extended flares on my YJ, but with the full-width axles, my tires still protrude about 3.5 inches. I bought a pair of removable mudflaps and fit them to cover the full width of the tire. Technically, I need to extend the flares, but I have not been pulled over for them yet. I've heard repeatedly from Jeepers that if you do the mudflaps with good coverage, the cops let the flares slide (I think they are just unaware of the technical requirements for flares and just focus on the flaps -- cops can't read and memorize every letter of Utah code, they remember key parts only).
As far as inspection goes, I wouldn't know anything about that, I just steal a new plate off somebody's car every year. J/K
If I were in your situation, I'd make the dealer provide you with a legal vehicle. However, you don't want them to do something too cheesy that you get stuck with. See if they'll spring for a set of these:
for mild tire sizes:
http://www.central4wd.com/store/itemdetail.asp?ID=8562
for wider/taller tires (I have these for my 35x12.5 tires and they fit just right - the sales rep tried to convince me that a Jeep didn't need flaps that big, but I'm glad I didn't listen)
http://www.central4wd.com/store/itemdetail.asp?ID=8563
hope this helps - good luck
__________________
Jason Potts
Information Technology & Services
Cephalon Inc - SLC
jpotts@cephalon.com
801.401.7495