I had a twinturbo Dodge Stealth that had the throttle stuck open, and I put it in neutral, hit the brakes, rolled into a parking lot, and then shut it off ... and that worked fine. I don't know why that wouldn't work with these cars too, although it was a 5-speed if that makes a difference.

It might've bounced off the rev-limiter a few times, but it stopped it. Be careful about shutting it off too early because you lose your power steering.