Most of the mods that are more likely to involve warranty concerns are ones that increase the stress on a stock component...so if you install a turbo, and blow the pumpkin in a smokey burn-out...,they might say the extra power was to blame for the pumpkin popping.

If you have larger diameter tires, and your center links are prematurely wearing, they might blame it on the extra forces involved in controlling the larger tires, etc.

This is why a good mod path includes beefing up stock liabilities to account for the potentially involved increased stress on stock components...such as a reinforced steering system if you are running larger tires, and frame reinforcement if you install a hitch, etc.

According to the law, they have to PROVE that the mod caused the damage to refuse warranty coverage.

Way back, I put in a FM converter in a brand new car (I was always on the cutting edge of technology...) My horn didn't work from the day I got the car, so on about the fifth visit to get them to actually fix it, they said it was because I ruined the electrical sytem when I installed the converter...I pointed out that the horn didn't work before hand either...so it couldn't have ruined it...we argued, I sent a letter from my lawyer ('s stationary...), and they recanted, and replaced the faulty horn, under warranty. (cars, sigh....)

I used to believe that I should wait for my truck's warranty to run out before making any changes to avoid conflicts...but now I feel that I'd rather wheel the newer more reliable rig with at least the possibility of warranty coverage for a failure, than to wait until I have an older, less reliable rig to first start wheeling without any possibility of coverage.

The X has had it easy so far, no warranty work needed, only a string of recalls, but the Jeeps were beat pretty hard, and the warranty even covered off road damage for me. I limped in one time in front wheel drive with a busted C-Clip/diff rear axle, blown radiator, the rig covered in and out with mud, and a spare with a blown sidewall, and the rear bumper wrapped up to the gas filler on one side, and the front bumper at a jaunty angle too. (Paragon, good trip...) - They fixed the spare, straightened the bumpers and replaced the rear axle, etc...and I paid zilch...they just took care of it, with the axle and radiator as the only parts officially covered, with Chrysler reimbursing them for the work.

If I'd waited for the warranty to expire, it would have been all my expense.

Does that help at all?