You can buy at CoPart without but you've got to buy their stupid subscription. I've bought a few things with them. You've got to pay in person and with a money order. I learned that the hard way at Vegas CoPart when I had to swap cash for a money order at dodgy loan center 5 minutes before they closed.
It doesnt work like that now at the SLC copart. I bought a dirtbike there recently. If you want to participate in their online auctions you have to use an online broker. Now, they make it kindof easy to do, but its another layer of bullshit and fees. For instance, i bought my DRZ400 for $2000 auction price and it ended up being $3000 otd after fees and taxes.
The fees arent generally that much, but you pay a base just to process and they go up from there. So research the fees as much as possible.
Also, im in the SLC copart all the time for work so i get to see things before they come up for auction. So i got to inspect the crap out of the DRZ400 before hand but you can still go there and inspect generally as an individual if you want. But the ladies in the front will make your life misreble if you do.
If you have something specific i can check it out for you next time im in there, just send me the lot number.