The deal, is that it is not a deal.
Sure, they look nice. But I've also taken a complete heap before and made it look great. A good looking heap, is still a heap.
You have to consider one thing. If the car is repossessed, the owner wasn't making payments on the car. And you have to wonder, if the owner didn't care enough to make payments, did they really take care of the car? They may have. They might not have. It's up to you to decide the risk on it. Also, a lot of seized cars, have been sitting for a very long time. Just because they're cleaned up, doesn't mean that they don't need a lot of new parts.
Just stuff to consider. I've found a few good deals, and also found a lot of cars that were just nightmares in a pretty package.