Dead Rising 2 SUV Keys information tips ? Need to know questions below

Dead Rising 2 Xbox 360

Iam going to be doing duplication methods with the bargaining books -

When I have the 12 Bargaining books , how do I keep repurchasing take the key buy again ? Or do I walk out the pawn shop leave the key on the ground to despawn and rebuy ?

Is the key a - key items do they go in the inventory ? And take an item slot up

When restarting story does the key go through to the new play through so you can get the SuV straight away like cash and level does

Also the Orange Car when is this usable

Any other tips and tricks for the suv and the key