I would recommend using 3M brand ruberized undercoating, it costs a bit more than the generic store brand stuff, but it lays on better and seems to be better quality. The only place I would worry about applying it would be above the catalytic converter or close to the exhaust pipes, as the heat from these may melt it.

The spray undercoating can be applied inside the doors, on the roof panel above the headliner, inside the quarter panels, etc. Once it dries, most of the smell will go away on the black type undercoating. 3M also makes a clear undercoating, made to be sprayed on the outside of the rocker panels, ete., then overpainted with the body color, "Body Schutz"? or something like that, that works well and dries with no odor. It costs alot more than the tarry type coating, though.

For more noise reduction, I've used fiberglass insulation, like for houses, stuffed into body openings behind the trim panels, to quiet some of the noise in vehicles. I also have added an an extra layer of carpet insulation felt under the OEM carpeting and found it really helps with road noise. The insulation carpet felt can be glued to the inside of the roof panel, above the headliner, and inside the quarter panels with strong contact adhesive, too.

Hope this helps!