I do several things before buying a new car.
1st, I come up with a list of about 5 models that I like.
2nd, I check Consumer Reports (C.R.) to see what they have to say about those models. C.R. accepts no advertising and no donations of products, so you get an honest opinion. And once per year, they survey their readers (something like 300,000 respond to the survey) on repair histories of autos. Reading their mag, is a lot better than asking a couple of buddies what cars they like (how many have they bought?).
3rd I check with my car insurance agent. You will be surprised at how much insurance rates vary based upon which make & model you buy.
4th, by now I am normally down to 1-2 makes & model combinations. So it is time for a test drive. Not with the dealer. I go to Orbitz.com and look for a car rental company in my area that has the make/model that I want. Renting from a airport location will add at least $20 to the rental fee. So I rent the car for 2-3 days and get used to it. I normally try to take it on my average out-of-town trip. Have done this 4 times in the past 10 years. Twice, I have decided that the model I had wanted, isn't right for me. Some people argue, this is a waste of money. But compare the rental fee, say $250, to what you will pay for the car. Isn't $250 a small amount to be sure you get what you really want?
Most people take a 5-10 minute test drive with a car salesman and then sign to buy the car. I think this is the biggest mistake people make. While you are driving, the saleman is telling you things to get you to imagine how it will feel to own the car. You cannot focus on checking the car out.
I once really wanted a Saturn SL2. On a short drive it was comfortable. On a long drive, the seat started to get uncomfortable (I'm 6-1" and 190 pounds) after about 2 hours.
Once wanted a Toyota Camry. Rented one. Didn't like the way it steered and the road noise.
Another thing. Once you decide on which make & model. Go to at least 3 dealers and get quotes - on the exact same make & model and options. If you live in a large city, try to go to at least 1 out-of-town dealer (rural is better).
When I bought a Honda Accord, I went to a dealer in the city limits of Richmond, VA. They wanted the Manufacturer Suggested Retail Price (MSRP) + a Fair Market Adjustment (FMR) of $3,700. I asked what the FMR was for. The salesman asked me - Why! Can't you afford to pay it?
I went to a 2nd dealer in town who wanted the MSRP.
I drove 30 miles to a small town outside the city limits and that dealer wanted the MSRP minus $1,800. I bought his.
I saved about $5,500 by taking 3 days to search. And I made sure that they were all Honda Accords LX with the same options.
I have owned Honda Accords, Civics, and CRV with no real problems. Over 200,000 miles on the Accord when my son took it as his.
After you have agreed to make a deal with the dealer, sit on your wallet. After you negotiate with the salesman you will think "its all over". It isn't. This is when customers make the mistake of letting their guard down.
After the salesman finishes with you, you will be sent to the Finance Manager, or Business Manager, to line out a few final details. This is where they offer you such things as pin stripes and undercoating or an extended warranty. Each item will cost from several hundred to $1,500.
Consumer Reports says these items are greatly overpriced and are not worth having. Many buyers feel like they just made the "deal of a lifetime" and want the best - so if the dealer says you should consider buying these extra options to protect your investment in the car - many customers will buy them. They should not buy them.
Good luck.