Adding Extra Sound Dampening

[SuperCoupe400]

I'm not really satisfied with the cabin noise level at highway speeds. Since the '93 SC400 didn't come with speed sensitive radio volume (not sure that ANY car did back then), it's just getting a bit annoying having to ratchet up the volume when making my way onto the freeway.

It's not the wind noise that bothers me as much as the road noise. The wind noise can be considerably deadened by just pulling shut the moonroof cover. But it's the road noise that I can't do anything about - other than switching to some non all-season radial tire or just one with a softer rubber.

So I'm thinking about getting a few cans of that spray-it-yourself automotive underbody sound deadening material to coat the wheel wells with. Has anybody tried this before? Even if you did it to another car, did it help any? Does this stuff dry to a washable finish? I just want to make sure I'm not coating my wheel wells up with some product that is going to act like silly-putty and get embedded with all kinds of dirt and never come clean.

If you've done it before, what product did you use and to what areas did you apply it?

Thanks.

[95_SC400]

Ok, heres what i did. I read on another forum that people found a MUCH cheaper alternative to dynamat extreme. Since i just got a sub in my trunk, i completely covered every spot inside the trunk area with it. Its $14 for a 6 inch by 25 foot roll. You get 2 of these and its enough for your trunk. I bought mine from Lowes, and i love the result. Its exactly the same as dynamat but 10 times cheaper. So you can get a couple rolls and do the interior of your whole car. Should take about half a day but i think its worth it in my opinion. here is the link to the stuff:

http://www.lowes.com/lowes/lkn?action=prod...017-81326-PS625

[SuperCoupe400]

Thanks, I'll keep this stuff in mind when I get around to the trunk, doors and other parts of the cabin. But first I want to see how much sound I can deaden coming through the wheel wells. That's the loudest part of the car at highway speeds.

[CloudNine7]

SuperCoupe400,

Did you ever have any luck? My SC400, which I totally love, has a lot of road noise as well, and it's only bothersome on loud, concrete roads that have rougher surfaces. So it's not the wind noise that bothers me, it's the noise coming from the tires against the pavement (I have top line tires, so changing out the tires won't help unfortunately). I'm very curious if modifying the wheel well would help, or perhaps some cushioning added to the cabin floor. I'm thinking the doors are well insulated given how heavy they are? I always feel like I'm getting in a space ship. :-)

If anyone can add to this, I'd love it! I spend a majority of my drive time on loud roads in the country, so this would be worth it to me.