The invoice will only come to you outside eBay to a personal email account - there will be no record of the "invoice" within eBay because it is not real. There will be a "live chat" button on the email to contact someone at "eBay customer services" who can put your mind at rest that it is all legitimate.This is part of the scam.
The con is that the money will be held securely by eBay and can be seen by both seller and buyer. Following this, you will arrange a meeting place and time to check over the vehicle and, if all is OK, you authorise transfer of the secure funds to the seller.
This will not happen. The money you deposited will disappear, you will not meet the person as arranged as they will not be there. There is no vehicle.
I hope this saves you a lot of heartache and time.