I agree with Craig... the only thing it will do is reduce the heat in a convertible, which it does well.
We used HVAC duct wrapping from home depot.
It has an adhesive back with about 1/4" foam batting and aluminum foil cover which applies just like the other sound deadening products. Works well with heat deflection.
We did use it in the doors but in hindsight would not, although they sound pretty solid closing.

The home depot stuff was much cheaper and less than $75 to do the entire car.

I'd certainly use it on the floor boards and center console. No on the doors and trunk.
Just my $0.02