What to say when a car dealer asks if you're paying cash or financing?

I’ve been buying cars with cash for years…

But if I needed to buy with a loan…My credit union has a great deal…

I first go to the them and apply for a car loan…BEFORE I even look at cars. They’ll tell me how much I can afford and approve me for that amount. Then they write me a check which is good for 90 days. All I have to do is endorse and fill in the amount (The amount can’t exceed what I’m approved for) and give it to the dealer…It’s just like paying cash. The check is fully certified too.