So, long story short, a house down the street sold, and the people that moved in have a blazer that has the LOUDEST muffler EVER. They come and go several times a day and night, and it's OBNOXIOUS. It's even more obnoxious when they let the car warm up and have it running.
Pretty soon we are going to have a sleeping baby who I will be DAMNED is going to be woken up by this asshole car.
Any nice way of telling them to fix it or I'm filing a damn police report? 
Rich was thinking an anonymous letter to them would be a start.
He doesn't especially want to start shit with the neighbors, so he doesn't want to call the police and file anything, but we're not sure what to do.
Opinions?
if you're going to write a letter, you just need to make a few good points, some ideas:
-Tell them to search google/google news for the term 'loud muffler arrest'
-vehicle can be impounded, break down the actual cost of this
-the longer you take to repair the more probability it can't just be welded but needs to be replaced
-won't pass inspection
-inspection can be revoked in a traffic stop [not actually sure that's true but they're probably not a very intelligent person so you can slip in a couple lies with a bunch of factual information]
-it's really fucking annoying and you heard another neighbor say he would call the police, wanted to give them a heads up to be cautious