Hello there!
Your question asks if you offer up your car as a demonstration that you will pay off your loan, would your car be used as collateral?
Answer: True
The reason why your answer would be "True" is because you're offering up your car for something that could not be very certain to do.
If you offered your car as a demonstration to pay off your loan, but you don't pay off the loan, the bank has every right to take the car from you, due to the fact that the car is on collateral.
Collateral is known as something that is "forfeited" or "security" for a repayment of a loan.
In this situation, you're offering your car as collateral if you don't pay the loan back. And if you don't pay the loan back, you're going to forfeit your car to the bank in order for them to use it as a way to get money to pay off the loan themselves. Banks, bail bonds, etc. usually have people put things up for collateral to keep a "safe" measure for the loan, due to the fact that they're giving people instant money. It's just a "security" or "safety" procedure banks due in order to get something in return if the loan is not paid off, so they won't be losing money or leave empty handed.
I hope this helps!
Best regards, MasterInvestor