They say confession is good for your soul.

I hope so because my soul has been troubled ever since I bought a new car.

In fact, my car-buying experience at a well-known luxury dealership was my biggest mistake of 2016.

I’m not using any names here because it wasn’t all the salesman’s fault. He just took advantage of my poor negotiating skills.

I showed up on a cloudy day and decided on the spur of the moment to abandon my 2009 BMW 335i.

It was a great car, but 2009 was an emotional time for me. That was the year I was diagnosed with breast cancer. And while I am definitely grateful that I survived, my life changed in ways that are still too painful to dwell upon.

But I didn’t even think about the unfortunate connection when I got behind the wheel and took the car for a test drive. My latest car purchase was just as thoughtless.

Like an alcoholic who has had one drunken episode too many, I am finally ready to admit I have a problem.

OPINION

Some women loved red-soled shoes and python handbags.

Some women love sparkly things.

I love the feel of a luxury car.

I also like variety.

The other day, my sister added up the number of cars I’ve bought in my lifetime and I was shocked. I’ve bought or leased nearly a dozen sedans, SUVs and a convertible. And I once drove a stick-shift car off the lot without knowing how — and lurched all the way home.

On this particular day, I had only intended to window shop.

But a few hours later, I was roaring down the street in a brand new bauble.

My husband didn’t say a word. After all, it was my checkbook that was going to suffer because of my impulsive action. And, of course, I woke up the next morning wishing I had gone to CarMax.

Because I had not intended to buy a car, I did everything (and I mean everything) wrong.

So when my sister told me she wanted to buy a used car, I saw an opportunity for redemption.

I made sure my sister was prepped and ready to deal when she walked into the showroom. It was a couple of weeks before she actually felt comfortable enough to make her big buy.

Talk about success.

My sister wasn’t just knowledgeable. She was borderline obnoxious.

But she drove off the lot knowing she’d purchased a great car at a fair price.

So ladies, if you’re thinking about buying a new or used car, walk in there like you own the joint.

And when the salesperson starts taking charge of the negotiation, remind him or her that it’s your money. If that doesn’t get them to back off, walk away.

I’m still wishing I had.

Also, there are a lot of good car-buying tips on the internet.

For instance, blogger Lisa Tufano, author of the “Think Like a Boss Lady,” writes: “If you’re a woman, then you’re an easy target. Car salespeople may assume that you are not a strong negotiator and can be easily swayed with some flashy language and charm.”

“Stick to the plan. Don’t skip ahead to discussing financing when you haven’t negotiated the final, out-the-door price of the car. Don’t volunteer information. Remember the power of ‘no,’ and be prepared to walk away at any time,” she writes.

There was one good thing to come out of my own car-buying debacle.

I’m getting over the car-crush thing.

Recently a BMW 335i with temporary license plates roared past and my heart didn’t even skip a beat.