Yes. This is called a "voluntary repossession". You're still responsible for the entire amount of the loan, so if the car is worth less than the remaining loan amount, then you'll have to make up the difference. Also, it's still a repossession, even though it was voluntary, and will appear on your credit. If you're not late on the payments yet you may do better to sell the vehicle yourself and use the proceeds to pay off the loan, as this won't ding your credit.
You can't just return a vehicle you can trade it in on another vehicle. If this is a lease you will have to pay early termination fees if you try to do this.
No, there is no extra charges on an insurance policy for a financed vehicle. Only difference will arise in the paper works, and it will mention that the vehicle is hypothecated.
I assume by "financed" you are NOT referring to a leased vehicle but one purchased with a new-car loan. I also assume the vehicle is still pretty new and has very low miles, which is why you mentioned "returning" it. Basically, you cannot return a vehicle. It's not like buying and returning merchandise from Wal-Mart. You must sell the vehicle. The dealer from whom you purchased it might be willing to buy it back, if it's like new, or perhaps you could trade it in for a different model.
Legally? Yes.
Any lender requires insurance if the vehicle is financed.
put sugar in the gas tank
What is a Delaer?
There is no easy answer for that question. There are a few factors that matter when you are trying to return a bought vehicle. Did the dealership give you the car on the basis that you were approved but then got denied within a few days of buying the vehicle? If that's the case, you should be able to return it. Each state has its own laws on this matter so depending where you live will depend on all your options. The term "haven't been financed" does that mean you bought it in cash? Is the dealer a "buy here pay here" place? I would need more info to better answer your question. As a rule of thumb, you can return the vehicle, if the dealer "thought" you would be approved but you weren't, that's not your fault. Unless you gave fraudulent info, that could be another story. If you want to return a vehicle because you found a better deal somewhere else, good luck, most dealers won't be interested in helping you return a vehicle under that scenerio. You still may have options, but that would depend on where you live, and the laws in that state.
If it is a used vehicle and the contract states that you bought it "as is", you can not return the vehicle. Unless you were somehow misled as to the deal, the vehicle, or the contract, and can prove it, you can not return the vehicle.
NO, a lease is simply a contract like a loan. DEFAULT of either calls for repossession.
No
Insure?? yes, register? NOT unless your name is on the TITLE.