Ok, tried to do a search, but couldn't find anything...
I dunno if I'm just being paranoid (probably am), but
when you turn the key to the off position, does it take
a few seconds for the engine to stop? I dunno if I just
started noticing it after driving different cars this
week, but the BMW 323 engine seems to stop almost instantly
but my s2k will idle roughly then putter out ~2 seconds
after I turn the key to off. Anyways, let me know if I'm
drinking too much coffee (aka this is normal s2k behavior)
or if I should take it to the dealer (*sigh*). Thanks!

 

My car shuts off immediately. It could be the brand of fuel you are using and the octane rating. Does it make a knocking noise when you shut it off? I use Chevron premium, and used Chevron plus (mid grade) in my '98 Accord also with no knocking, and smooth idling. Some brands of gas are worse than others.

A family memeber's Prelude once ran really funny, with knocking, and the mechanic said that he'd never seen a gas that was so yellow (yes they bought cheap fuel, from a no-name station), they switched to Chevron, regular grade and never had any problems since.

 

This sounds like either bad gas or carbon deposits from using bad gas. When you turn off the ignition you cut the spark. If your fuel is to volitile, octane too low, it will detonate without a spark, just from the heat and compression. Carbon can also build up and glow like charcoal causing ignition. Start by using the a different brand of gas, the best you can find and see if that helps. You can also try some octane boost.

Do you get "knock" while it's running?

 

Back in the early days of smog control devices, often not only crude in design, but also in function, a phenomenon called "Dieseling" was common. Unburned hydrocarbons and carbon or particulate deposits would continue to burn for a few seconds after shutting off the ignition. I seem to remember that big Ford LTD-like cars were most notorious for this. It sounds like a trip to your friendly dealer might be in order, especially if you are able to duplicate the problem for them. My car hasn't experienced any such problems. Maybe you should also curtail your coffee consumption.

 

Hmmm, I've been running 92 octane from Shell, granted shell might not be the "premium" brand, but it shouldn't be THAT bad hehe. I've setup a dealer appt, and I'll look into some
octane boost. I don't get knocking during normal driving, but I just find it wierd that the engine takes a sec or two before it actually stops. Only have 3300 miles on the car - carbon buildup shouldn't be this bad at this milage should it?

 

This is NOT normal. The only engine that "might" continue running after it is shut off is a diesel and even these nowadays don't do this. There is something not right here. As far as Shell gas is concerned, the last decade or so I have not been able to run 2 of my cars on Shell Gold. My Grand Cherokee 5.9 Ltd. and my Viper would "ping" when under load. Only after I put 104 Octane boost did they run well. I changed to Esso and the occassional tank of Mohawk (10% ethanol to give 94 octane) in the cold months. No problem with these. Try the octane boost. If this doesn't help take it to the dealer.