I have a 2009 WRX with about 40k miles on it.
More than once I've had the engine bay underguard (or whatever you call that big plastic protective piece you need to remove before doing an oil change, etc) come loose, in one case on the highway to the point where it disintegrated before I could figure out pull off the road and figure out what was going on.
The dealer replaced that underguard under warranty, and now the new one has found its way loose (could be when I scraped it going up a buddies driveway the other day). As soon as I heard the tell-tale wind noise combined with an occasional scraping noise (when the guard would contact the road) I pulled over and removed the damn thing myself.
Anyway, went into the dealer for some routine maintenance and they noticed the guard was gone. They want me to bring it in next time so that they can put it back on for me, free of charge. They seem to think it is important enough to keep on (vs. leaving it off, which I'm otherwise tempted to do).
My question is, how important is that underguard piece? Does it really protect the underside of the engine bay from rocks and such enough to warrant messing with it? Better aerodynamics?
I know it catches spilled oil/coolant/etc, should there be any of that (fortunately on my car that isn't (yet) a problem, not to mention I park it in a public garage most of the time).
I'm really tempted to leave it off unless someone can point out a good reason to keep it on.
Thanks in advance for your help.