Vehicle Area Treatments
Treat vehicle doors to block traffic noise and wheel and engine noise entering through their front and rear edges. In addition to reducing noise levels, treated doors improve the performance of stock or aftermarket door mounted speakers and sound like they belong on a luxury car when you open and close them.
I always want to treat the roof. If there's a sunroof, it’s slightly less critical, still almost always worth doing. The roof is a large, often highly resonant panel, directly above your head.
If a sudden rain storm scares you - treat the roof.
If wind noise from the roof annoys you - treat the roof.
If you want to take advantage of the best place in a vehicle to use an absorber - treat the roof.