You are right on those points. And yes because some dealers know about this law, they always try to find the way to blame everyhing on the mods or alteration. THe thing is (and this happened to me a lot with my previous car) that if they look at your car, open the hood, or see any modification, they cannot void the warranty of the car.
You know every law has its flaws they never cover everthing they have to. I guess thats when your personally has to come in place. In my case, the knowledge of the car, the knowledege of the parts I installed on my car, the law and most of it the respect against the Service Manager and the techs, helped me a lot.
Cause even if the law protect you, the dealer can bring the card of "we have the right to deny service and dont deal with this customer"
