W210 key won't turn

[beevly]

2002 E320 - key will still operate door locks and windows. Usually I hear some mechanical unlocking noise as soon as the key is inserted in the ignition, after which it will turn, but now no noise and it won't turn. Tele-aid had the dealer call me on my cell (nice feature, never had to use it until now) - he thought the chip in the key itself was bad. They've ordered a new key which should be in tomorrow - he'll come out to the car then and program it.

Questions - are the keys known to go bad, or is it more likely a problem with the ignition? A quick search turned up a few W210 ignition failures and replacement questions, but not much on the key itself. The car is stranded in the company parking garage (at least it's safe there), but there is pretty low clearance in there. I don't think a tow truck would fit. If the new key doesn't solve the problem, how can the car be moved to the dealer? What are the options?