OKLAHOMA CITY - Here's a practice News 9 wants to tell you about -- when a dealership allows you to drive your new or used car off the lot only to discover your financing isn't approved.

Sometimes when this happens, you sign an agreement that states "subject to final approval," then when you're not approved, the dealer or car lot can charge you a much higher interest rate than you expected. 

So here are some ways to protect yourself, according to ConsumerAffairs.com

First, don't drive the car off the lot unless the deal is set in stone. Don't rely on verbal assurances. Some dealer finance managers will try to smooth over ugly parts of a finance contract, especially those with bad credit. Know the market. Don't accept a finance contract without checking to see what the going interest rate is for your credit category. The truth is -- they're tacking on several points of interest onto the loan over what the bank offers. 

To get a real-time snapshot of average car loan interest rates for your FICO score, use the loan calculator available at MyFICO.com.