Just had 30k service done on 98.5 1.8TQMS, roads in Northeast are covered with patches of frozen slush, and I'm hearing a mysterious rattling sound when I hit certain bumps, as if something outside of the cockpit (unclear where) is loose. A muffled clatter-type sound. Car drives fine. Any ideas?

The under engine splash shield has been reported by at least one person to have caused a rattle under the car. Check to make sure all the clips are in place. (Two in each wheel well, three at the front, and three at the back of the shield). The ones at the back of the shield, if unattached, would be especially prone to rattle due to the metal strap they are attached to. You should be able to check this without raising the car. Just tap/bang on the underside of the shield to see if it seems firmly attached.

I've tried poking and tapping as you suggest, so far without discovering anything apparently loose. Interestingly, an old posting suggests stones caught in the splash guard. Another suggests a bad sway bar bushing. I'm still looking. Incidentally, where exactly are the clips that hold the splash guard in place?

The three front clips (really metal "screws" that you need to turn about 1/4 turn to release) are located evenly spaced across the front of the shield right where it meets the front "spoiler" panel. The rear screws are similar, but at the back. The ones in the wheel wells are at the bottom front, and are plastic.<p>It is possible to completely remove this shield without the car being raised up, even with sport package. How do I know? I dropped a screwdriver down there yesterday and the easiest way to get it out was removing the shield. (But I also got to verify that my power steering fluid leak is gone). If you remove the shield, pay attention to how it fits, particularly that it fits BEHIND the plastic wheel well liners.

Here is an example of how A4.Org really helps people. Guess what were missing from the fore section of my right front wheel well? Both screws! I also found little "rocks" of ice hockey-pucking around in there. I've put some temporary plastic screw anchors until I can get the real things from the dealer. I'll test drive it later today, when I'll know for sure. Dale, you are a good man.