Yep, getting a new set of wheels is one of those wonderful sources of high-octane excitement -- but don't get too revved up.

Car buying is, or should be, a calculated decision. It's a major purchase. So, before you go cuckoo for that coupe or raving for that roadster, consider these top 6 mistakes car buyers make.

1. Buying the wrong vehicle: Sure, those SUVs look big and cool, and dealers are dealing. But do you need one to drive the mile and a half to bingo every Sunday? Is that racy red sports car really the best choice for your family-of-five-kids-and-growing?

2. Getting emotional in the showroom: If you fall in love with a car, be sure not to overreact and get too eager. Give yourself some time to sit back and make sure it's the car for you. In short, don't let your heart rule your head -- it can lead to aching in both. Also, keep a grasp on reality. If you can afford $20,000 and the object of your affection lists for $30,000, you might be able to negotiate it down to, say, $27,000, but there's no way you're going to be able to buy it for $20,000.

3. Choosing a dealer by location: No, dealers are not all the same, not even for the same exact makes and models. Ask around. Learn from friends' experiences. Also, determine your dealer's Customer Satisfaction Index, or CSI, which is a ranking generally maintained by individual automakers for the dealerships that sell their vehicles. Ford, for example, gives out what's called the Blue Oval Award to dealers with a top ranking. The CSI is a reflection of how well an individual dealer satisfies its customers in sales and service. Ask your salesman about the dealership's awards. If he balks, you should walk. You can also check a dealership's complaint record with the Better Business Bureau.

4. Talking trade-in too early: This is another easy trap to fall into, because dealers love to play the trade-in game. Don't let them muddy the waters. Negotiate a satisfactory price for the new car, and then bring up your trade-in. Another thought: If you bring in your old car full of trash and covered in mud, the appraiser will rightly assume you don't put much value on it yourself.

Going it alone when you need a helping hand: If hassles give you headaches and negotiations make you nauseated, turn it over to an auto broker or a service such as the AAA Endorsed Auto Buying Program, which nets members special pricing through authorized dealers.

6. Forgetting that it ain't over till it's over: Or, in the case of car buying, it ain't over till the business manager sings. You may think you have bought your car once the sales manager shakes your hand and tells you what a great deal you got. But beware the business office, often called the finance and insurance office. Dealers often make as much money in this room as they do on the showroom floor. Insurance, dealer add-ons, extra fees and interest rate changes are among the common ploys you could get clobbered with on your way out the door.