Essentially, it would make the sub hit backwards, causing it to push inward. Because the stock box is a sealed enclosure, it seems to me as if there would be a greatly increased risk of blowing the subwoofer. :shrug:
I would also be interested in seeing pictures of this seat conversion. There are a couple of late model Taurus SE's and SES' in local junkyards that would make great candidates for the swap. Would the electrical connectors for lumbar, etc. plug right in?
Is it possible that this sound could be coming from the instrument cluster itself? I know that my speedometer cable needs to be greased, and it makes a bit of noise at lower speeds.
I have locked the keys in the SHO countless times. Exactly 6 days after I bought the Miata, I locked the keys in it, thoughtlessly. (And yes, the top was up.) I blamed it on the SHO and that damned (wonderful) keypad.