I'm hearing differing opinions on which is better polyurethane or fiberglass spoilers/ground effects. I'm thinking about getting the RMM 1 piece spoiler which is polyurethane but I've heard some negative opinions about polyurethane. Also Sewell Lexus is offering CL members the stock GS spoiler made of polyurethane already painted for $249 shipped which is an excellent price.

Does anybody have any opinions as to which material is better and why?

 

Both have their pros and cons. Poly kits are heavier and once you damage them, they are pretty much not worth repairing. However, they are usually more durable and don't break as easily as fiberglass. Also, if the mold is bad (warped), the parts don't tend to look or fit well.

Quality fiberglass (not the crap you see on most ricers) is also strong and do flex some so they're not as fragile as most people like to believe (the cheap ricers ones made by knock-off companies are though). It's lighter and it's much easier to repair and modify.

For the trunk spoiler, if you like the OEM design, I would definitely go for the Sewell deal. It's a steal.

Honestly, if you pick a poly or a quality fiberglass kit, you should be fine...

 

manaray pretty much covered the highlights, I just figured I'd add the fact that there are far fewer urethane kits available than fiberglass.

 

I know, it's an excellent deal considering that it comes painted. My problem is that I really like the slightly more aggressive look of the RMM 1 piece spoiler. It's similar to the stock one but it kicks out a little farther and the ends of the spoiler almost reach/touch the C pillars. I can get the RMM one for about $260 shipped but then I still have to paint and install which will be about another $250 or so. Tough choice when you factor in cost but I think I'll spend the extra money and get the one I like. I'll make my final decision after I get a look Johnny Mo's RMM 1 piece spoiler. I'm hoping he can make it to the next CL meet on November 10th.

 

That's the right attitude. I've never have one regret buying the actual item I wanted instead of settling. Especially since it's only a $260 difference...not a $2,600 or $26,000 difference.