When I went to herb chambers infiniti, they denied me service saying my greddy sides were too low. So i went to kelly infiniti, and they actually took the time to put wood under the tires and get the car on the ramp. Ever since then, if i ever needed anything, I go to kelly, and they always take care of the car.

 

When I dropped off my boss' car at the dealer for tranny work I wrote them a list that looked something like this;

Follow these rules or you will be phoning me every 5 minutes (519-xxx-6587)
Allow only head of service to move this vehicle.
1. When you get in close the door and apply brake
2. Find buttons under the dash, enter on buttons XXXXXX said code
3. If you open the door, enter the code again
4. before putting the car in gear, air up the suspension. minimum 37PSI front and minimum 37psi Rear.
5. when airing the car out make sure the wheels are straight and steering wheel 100% up and down, if not you will be buying fenders.
6. Do not touch the wheels, the locks you think are on them are not what are on them. You do not need to remove the wheels for transmission work.
7. Do not touch suspension parts without request.
8. When closing the door and parking the car, hold the lock button for 3 seconds or the car will low jack and you'll need to enter the code again.
9. Don't open the trunk.

This was a dodge dealer I have no relationship with and they had no problem with the list at all.

 

I can see why the dealerships may deny service though. I'm sure they don't want to pay to replace broken/cracked lip kits, and I'm sure if they DID break something, you would scream bloody murder at them

It depends what you have to go to the dealership for though (ie warranty work), finding a more willing shop (one with knowledge in modded cars) may be better in the end.