You negotiate a deal on a new car with the salesperson, and maybe you feel like you got a good price.

But the toughest part may be just ahead. If you’re seeking financing, you will have to negotiate with the auto finance manager. And the strategies that manager uses against you can rob you of the bargain you got from the sales person.

Now you can learn some of those backroom secrets. Edmunds.com, an online source for automotive information, has published an online series called the “Confessions of an Auto Finance Manager.”

 “The auto finance process is extremely complicated and foreign to most consumers,” says Philip Reed, a senior consumer advice editor at Edmunds.com and co-author of the series. “It’s no surprise consumers often make poor decisions in this environment.”

Tips from “Confessions” include:

— A finance manager can get wholesale lending rates, but will quote you a higher one to maximize the dealership’s profit. So, go into the dealership with a pre-approved loan. Or, at the very least, know your credit score and what interest rates you might qualify for.

— A finance manager might only offer financing in a package with add-ons that you don’t need or want.

Avoid overpriced add-ons. You don’t need to buy an extended warranty, for instance. The bumper-to-bumper warranty will last three years or 36,000 miles. The powertrain warranty often last up to 75,000 miles. And if you really, really want an extended warranty? Don’t buy it at the first price quoted. The mark-up is 100 percent, so the finance manager has plenty of room to go lower.

— And paint protection? Forget about it. It’s a “glorified wax job.”

— Check out the price of the car you want online before going into the dealership. Take that with you into the dealership.

"Confessions" is cleverly written and has useful information. But it makes you wonder: Does anybody out there like to negotiate on a car?