I have a 2007 Passat. In the wintertime, the cover below the engine makes a rattling or “crinkling” sound. When I first heard it, I thought that a plastic bag had gotten caught beneath the car. I have had the car in twice to the VW dealership. They tell me that no one else has ever complained about anything like this and that there is nothing to be done. Anyone else had this problem?
Maybe a rattling heat shield for the exhaust system? However, you described a plastic, not a metallic noise.
If you’re DIY prone, jack the car up, install jack stands, and tap on things underneath using a rubber mallet. You may be able to recreate the noise. If not, find another mechanic to take a look at it. Maybe VW could find the source if the car was out of warranty.
Yes, as I was looking through descriptions of other problems I saw that the heat shield had rattled on other cars. This sound is distinctly in the front and I was thinking that the heat shield was in back. That is a good idea to run the car up on jacks and look at it. The sound is kind of a combination metal/plastic sound–like the noise those windshield inserts made of the NASA-like crinkly metal stuff makes!
Shields can be towards the front as well.
Problem Solved!! On my regularly scheduled inspection, I told my VW rep once again about the noise. This time, the mechanics took time to look around and found the problem–the noise was coming from the front bushings on the front control arms. They replaced the front bushings, replaced the wishbone mounting, and I haven’t heard the noise since. Third time was apparently the charm. Thanks for tips, which helped me to describe my noise a little better!