How does Capital one Blank check work?

How does the interest work?
In other words lets say I apply for and am approved by Capital one for $30000When do I know what my interest rate is? And what if I am approved for $30000 but I only use $25000; does the interest rate change?
Any info would be great.

When you are approved, you should know what your interest rate will be. If you don't know, or no one will tell you, then don't use that lender.

How much of the approved amount you use shouldn't change your interest rate.

DO NOT go shopping until you know ALL OF THE TERMS.

If you're approved it will be a set rate that is told to you along with the credit limit, from that point its at your discretion how much you want to spend. Although I think you have to spend at least $7,500 or something like that.

Used it and loved it. Up front, no surprises. They give you the limit you qualify for and the interest rate and you literally fill out the blank check to the dealership when you buy the car. The good think about this is that they do not require a down payment. I used lending tree, which includes capital one.