This just happened to me..
Trying to be a prudent shopper I started searching the internet to check for the best price and to find a vehicle I wanted.
This is where the problem started.
Some dealer sites have tricks they use to get your info. I wanted to check the value of my trade-in and see their "special" internet price. So you fill out their form with your name and other info (mandatory info to get an answer)....they start shopping around for a lender.
I didn't find this out till later. I looked at dealer sites in 3 different states up to 5 hours away. I have been searching about a week.Everytime they do a lending search your credit score starts dropping. Now all I was doing was checking around. I never told or authorized any of them to do any searching about a loan.
I did my credit reports and checked my credit scores before I actually went shopping. I found a local dealer (1 hour away) that showed an internet inventory of hunderds of vehicles.
Another trick. I thought with all the dealers that closed this guy must have taken in a lot of closed dealer inventory. 
I get to the dealer and tell them I wanted "X" vehicle I saw in their inventory. They show every vehicle they have access to from any number of other dealers in a 10 state area.
The vehicle I want isn't even in the state. I told the sales lady their site sucks. The only reason I drove an hour was because I stupidly thought they had the vehicle here. TRICKY on their part, STUPID on mine. I should have walked then.I could have gone to a dealer 3 miles away from my house.
So we start to work a deal on the out of state vehicle. After 4 hours they start to shop for the loan. But then the price can't be finalized because of the issues involved in getting the vehicle here. The sales manager asks me my credit score. Which I PAID to look at days before. He comes back and says the score I told him and what is coming up isn't the same.
He acts like I'm lying about it. So what I PAID to see was a waste of money.Here is what I have determined.
Your credit score is controlled by a comuter program of some type. The computers are all tied together.
Everytime you use a credit card or apply for a loan...instantly your credit score is effected and changes.
Never pay to see your credit score...because it constantly changes. The score you just paid to see has passed and is of no use now.
Everytime you make any type of installment, loan, credit card or utility payment ..your credit score intantly changes.
Paying extra or above the minimum on any payment regularly doesn't add to or improve your credit score. Which should make your credit score go up.
Rich banks want to suck the poor people dry.
30 seconds late on any payment will crash your credit score instantly.
Any excuse to lower your credit score is good enough for them. It makes somebody more money. It takes an act of congress to make your credit score go up. It's like interest rates or gasoline prices. Just thinking about them makes them go up very fast. They are always very slow to come down.
A new vehicle is the second biggest item next to a house you will buy. The credit report/score places should realized people will be shopping around for the best price. It's not like buying a pair of shoes. Multiple loan requests from dealers should not be held against your credit score. Dealers shouldn't be shopping for a loan without you actually telling them to do it.
With the cars sales market in the dumpster they all want to make a sale so they have these little gimmicks to try to lure you to their dealership.
Technically all of these unauthorized dealer loan inquiries or credit searches or whatever they did, lowered my credit score.
Use the internet to shop for the best price or check inventory but don't give any dealer you don't plan on buying from any info that can be used to do unauthorized credit searches.
Knowing now what I just found out the hard way (and I had other people tell me it has happened to them) I wouldn't have done the internet thing.
I would just go to the closest dealer and let them find the vehicle and do the best deal with them. That way there won't be multiple searches showing up against you on your credit report. Each search whether you authorized it or not has a instant negative impact on your score. Makes you qualified to pay a higher interest rate.
The banks and or big government have got this down to a science. It's a way to extract more money from your pockets. The rich and powerful want poor people to use credit cards so they become more rich.
Too much power is being given to the credit report and credit score. It can be used to keep you from getting a job. Get you dropped by your insurance company. Used to make you pay higher conventional loan interest rates.
If you don't have a credit card you can't get credit. They want people in debt. If you use your credit card too much and your balance is to high it costs you higher interest and lowers your credit score. You can't win.
The answer is have credit cards that have a tiny balance you can pay off every month. Don't use is except in an emergency. The get a real loan to pay it off quickly.
I am reevaluating how I look at and use loans and credit cards. The value being placed on your credit score has increased to a very high level. It will control your entire life. From employment (whether they hire you or not) to car insurance rates (and if they even want to insure you or drop you.) To the amonut of credit card and loan interest rates.
Rich get richer and the poor get poorer.
It's a good thing I don't need a vehicle. I just wanted to take advantage of the great incentive deals.
Whether it was on purpose or accidentally those car dealers brought my score down. It works in their favor because you have to pay a higher interest rate and they will make more money. So the good deal on the front door goes out the back door.
I have heard they now examine the places and purchases you make. And there are certain things you shouldn't put on credit cards because they can effect your credit score.
Whose money is it anyway. I'm paying for it, not you.Food shopping, por-no, fast food, bar tabs......all drop your score.
Cash is still King. Years ago if you bought anything on credit you were looked down upon like a "low life." Those days are coming back.
But they like it because it makes them richer.
It's MY personal info coming in the mail. The dealer had it on his screen in literally a few seconds and he paid nothing. I saw the screen. He showed it to me.