[Tireiron]

Here in Massachusetts in the states by the rule of the law no modifications to a vehicle other than OEM replacement are allowed. Anything that is not visible or noticeably changed will not draw any attention or give any issues, like upgraded brakes and suspension components. However if there were an accident that caused loss of life and they had to do an investigation and found aftermarket or modified parts it would be very easy for them to blame the accident or failure on the modified parts. There is no certification you can get for different or upgraded parts.

Noticeable items like exhaust or lowering/lifting can cause major issues with our yearly inspections. There are very strict laws on lowering/lifting (no more than a 2" change from OEM) and no modification of the exhaust from OEM is allowed. They do not have a decibel limit or anything for the exhaust, it just states strictly that no modification from OEM is allowed. The exhaust one is very tough to deal with especially in older cars where they rot out due to our winters and the salt used. An OEM SVX exhaust, if you can find it, is over $3000 from the dealer, where I can bend and weld up an exhaust for like $300 which sounds very good but is louder and modified from OEM.

As far as resale goes, there is no certification so there is nothing to worry about. You sell things as they are and that is it.