instrument panel cover

I posted a couple of weeks ago and got some good advise, so thought I'd try again. I just bought a 99 Maxima GXE, perfect inside and out, looks new. Perfect in every way except one, the instrument panel glass, or plastic I guess, has streaks on it. Guess someone used a spray cleaner and it got inside the plastic. Is there any way to get these streaks out short of replacing it. Body shop guy said use wax, and I did, and it did help some. But I think it was just taking off the residue from the outside. Didn't know if there was a product that would help or not. If I do have to replace it, is it a hard job. Any help appreciated. Thanks