On some of my previous cars, I learned of a fairly simple hack to disable the seat belt warning chime - on a hunch, I tried the same procedure that I used for my Subaru, on my Cayman, and lo and behold, it worked. Now, in anticipation of the usual protests ("Why don't you want to wear your seatbelts?" . . . yada, yada) I issue the following:
DISCLAIMER1. I always wear my seatbelts when driving.
2. I always make sure my passenger(s) are wearing their seatbelt(s) when I'm driving.
3. I strongly advocate that everyone always wears a seatbelt.
4. If you choose not to wear a seatbelt, then you are only proving Darwin correct.
Now, that being said, there are times when I remove my belt, e.g. at a drive-thru, ATM, etc. to get in my wallet, and don't like to listen to the incessant dinging. I also plan on using racing harnesses at the track, and would like to shut off the chime without resorting to other measures.
Now, interestingly, the procedure that I have used on previous cars was reversible; simply by repeating the procedure you could toggle the warning chime on and off. For some reason, I have been unable to restore the original warning chime, despite repeated attempts. (It probably could be restored by either disconnecting the battery or taking it to the dealer to have it reprogrammed - I don't know). Because of that please observe the following:
WARNINGThe procedure described below may result in the permanent disabling of your seat belt warning chime as programmed at the factory. If you do not want to disable your chime permanently, then don't do it!
Okay, so here's the procedure:
1. Turn your key in the ignition to the On (second) position (don't start the engine). Don't connect your seat belt yet.
2. When the initial seat belt chiming stops, quickly insert and remove the seatbelt (you can hold down the release button to facilitate this - just make sure to insert it all the way) 10-15 times as fast as you can (i.e. less than 20 seconds).
3. Turn the key off, then start your engine and test to see if it works by driving over 10 mph on a safe side street without your belt. If it didn't work then try again with a different number of insertions.
Now, my chime does not come on at all if I don't connect my seatbelt before starting the engine (the little red warning light on the dash does come on however). If I disconnect my belt while the engine is running (like at a drive-thru) it will chime 7 times, and then stop.
I don't know how or why this works, but it is a big improvement to me.
LATE ENTRY (1/20/07): I have tried disconnecting the battery, but that did not return it to the original state.