Problem is that suspending someones license doesn't really prevent them from driving if they're really intent on it. However, seizing the car/truck/SUV/bus of a repeat DUI offender and destroying or reselling it through govt auctions would be a sufficiently strong financial penalty to make them really think about it. You can drive without a license but it is quite a bit harder without a vehicle. The idea also works if the car was borrowed as it'll pass the message that if you lend a car to someone who is drinking/drunk/unfit to drive, you're complicit.
As for stolen cars, it's a different situation entirely.