If you've signed up for a Starter Membership you're only allowed to purchase one car and you may only have one active bid at a time. If you'd like to bid on additional lots, you'll need to upgrade to a Preferred Membership.
If you have a Preferred Membership, you're free to bid on and purchase as many vehicle as you'd like. You'll need to submit an additional security deposit for each car you'd like to bid on. Your security deposit should be a minimum of $400 or 10% of your desired maximum bid. For example:
A $400 deposit will allow you to bid up to $4000 on one vehicle
An $800 deposit will allow you to bid up to $8000 on two vehicles
A $1200 deposit will allow to you bid up to $12000 on three vehicles