Some of the stuff there is police auction by real police departments.
But most of the stuff there is simply somebody selling junk.
I do alot with ebay and have 100% good luck, selling and buying. About 500 transactions now. 4 of them with me buying cars, 2 sight unseen before being delivered.
Read the auctions, look at the feedback, look at feedback given as well, and ask questions. Pay with PayPal and for the most part, you are covered. I only buy from people with 100% rating in the last two years. Any negatives and I stay away.