There is no budget way to improve it unless you are very handy with your hands and can DIY including removing door panels, seats and floor mats.

Otherwise you can spend 3K - 4K for some improvement but it's not going to be spectacular. Road noise is low frequency rumble and it's very hard to reduce.

Unless the money means nothing to you I would just leave it. Dismantling many items can also result in ratlling, humming or squeeking later if clips are broken.

This post has been edited by kluseng: Dec 19 2016, 11:27 AM