I have a '95 YJ and I love to wheel it and drive around town, but driving on the highway is a drag.  It has a hardtop and the 4- banger and I can live with it but it makes so much noise I swear that I am going to go deaf one of these days trying to make my stereo compete with the noise.  I was wondering if there was anything that would make the road and engine noise quieter.  Thanks.  

This helps a little with looks, acoustics, and adds a thermal barrier. Click here for more info.  

http://www.crutchfield.com/g_181250/Noise-Deadeners.html?tp=2277check out crutchfield too... they sell soundproofing material that will mold to your floor pan and can be covered by carpeting  

i threw a 3/4" rubber mat in the back of mine, under the carpet. took alot of the road noise away. as far as the hard top, check the links ftgiles and gotmike gave ya. or check out     coloradojeepman.com    he has an accustical barrier that mounts into your hard top