I Concur! Mass. inspection laws suck. Along with many other laws.
Being a lifelong resident of Mass., I have dealt with these absurdly strict inspection rules for over forty years. As time goes on they get worse. There are many vehicles on the road here that don't comply with all the regulations. If someone has a friend that is an inspector, that inspector will be lenient with him. Some inspection stations are more lenient than others.
For those who don't know; a couple of examples of how strict our inspection laws are: Any safetry related equipment in stalled on the vehicle at the factory must be in good working order. Windshield washers are considered a safety item because they clean the windshield. If they don't work, even if only because there is no fluid in the tank, the inspector is supposed to reject the vehicle. Many vehicles have parking lights with two layers of plastic that make up the lens. If the outside layer is broken or cracked, even though the inside layer is intact and no overly bright light is exposed, the vehicle is supposed to be rejected.
If your vehicle fails inspection for a safety related item, there is no grace period or time frame to get fixed. As the law reads; you must stop driving the vehicle immediately refrain from driving it until it is repaired and re-inpected. This doesn't even allow you to legally drive the vehicle home or to the place where it will be repaired.
As far as aftermarket exhaust goes, I believe that the recent bill to restrict exhaust system to original equipment was stuck down.
However, if your vehicle came from the factory with a catlytic converter, it must retain at least the same number of converters that it came with. Even if your vehicle no longer needs to pass emissions testing.
When tinting windows, you must take into consideration the fact that factory glass has about 3% tint in it and this must be added to the % tint you are putting on the windows. I'm not sure what the limit is here. 35% or 33%. and this only pertains to the driver's door windows and front passengers door window. No additional tint is allowed in the windshield other than factory. All other windows can be as dark as you want, even painted as long as there are outside mirrors on both sides of the vehicle.
I have found that even though your vehicle may have some mods that make it illegal,the way you present yourself on the road can make a difference in wheter or you get hassled by the police.
In Mass a chews it (my home state), I believe the vehicle inspection laws are way too strict. At the same time I think some inspection is a good idea. I would not like be on the road with thousands of cars with bad ball joints or tie rods with wheels just waiting to fall off.