Wing spoilers weigh more then lip spoilers, lip spoiler should be factory tacked on with some very sticky trim adhesive you may want to peel the lip spoiler off and see how different the paint under the lip spoiler looks from that around it that was not covered by the spoiler (as the wing spoiler wont cover the line of unfaded paint that the lip did) and you may notice an unsightly line of slightly different colored paint under where the lip spoiler was. I peeled off the factory door ding protection trim from my old 08 at 80k miles and the paint under there was a slightly different shade (factory color, just not weathered) and you may see this as well, and if your like me no one else will ever notice but that's all you will see when you walk up to your car so I ended up putting them back on a week later, but the wing spoiler will need bolts/screws to hold it down properly for any length of time.