I've seen on 2 occasions, an Xtreme clutch explode and rip firewalls and engine bays apart. One was a Mazda RX7 and the other was a Holden VL Turbo.

For this reason, I'd never run one in my car. Even though they may be fine now, or maybe it was a once (or twice) off situation, I thought it was never worth the risk to run them in my cars.