There are all sorts of requirements that the inspector can fail a vehicle for. Down here in Moab the inspectors / local LEO's are more relaxed, but the state police will write tickets for no mud flaps.
My inspector said that the state patrol will often pour water on the fender flares and if it rolls off and hits tread it fails, otherwise you are ok.
Mud flaps should be kept in the vehicle and easily attachable (Not zipties) so you can install them should you get pulled over for not having them. I will be headed up north this week, hopefully I make it there and back w/o having to install the stupid looking flaps!
Bumpers can be an issue among other things. Here is a link to the inspection requirements: http://publicsafety.utah.gov/safetyi...T%20Manual.pdf
Best bet is likely to find a off road shop that does inspections and go to them for your inspections.
Jason - KB0WLI
2008 Black JKU Rubicon
RIPP Stage 2, RockHard Bumpers, RockKrawler 3.5" X-Factor & Fox 2.0's, Nitro Sleeved, Artec Trussed & Gusseted, Synergy DL Flip, Energy green Spyder Louvers, 37x12.50-17 Falken Wild Peaks wrapped around 17x9 XD Addics