Robbie, Do a search on unlimited products. They do not have a very good reputation on here. This was the last thread about them. http://mmb.maverick.to/showthread.php?t=63847&highlight=unlimited+spoiler
They probably keep going because the bulk of their products are used on race cars where fit and finish isn't as important. This is based on opinion, not fact!!
I've never seen a 'glass part that didn't require a bunch of tweaking to make it fit right. My son bought a Glasstek (supposed to be one of the best) cowl hood for his MCSS and it needed 3/4" ground off the rear edge just so it would line up with the fender. Just keep in mind, no matter what 'glass part you buy, it'll need work to get it right...
Unless you buy from MaverickMan...his are perfect fit out of the box. But I guess technically they are carbon fiber, not fiberglass. And you will pay a bit extra to have the perfect fit.