I think you are a little confused.
If you have 10.000€ in cash for a car, but you decide instead to invest that money and take out a loan for the car at 2,75% interest, you would have to withdraw/sell 178€ each month from your investment to make your loan payment. If you made exactly 2,75% on your investment, you would be left with 0€ in your investment when the loan was paid off. If your investment did better than 2,75%, you would come out ahead, and if your investment did worse than 2,75%, you would have lost money on your decision.
Having said all that, I don't recommend borrowing money to buy a car, especially if you have that amount of cash set aside for the car. Here are some of the reasons:
Sometimes people feel better about spending large amounts of money if they can pay it off over time, rather than spending it all at once. They tell themselves that they will come out ahead with their investments, or they will be earning more later, or some other story to make themselves feel better about overspending. If getting the loan is allowing you to spend more money on a car than you would spend if you were paying cash, then you will not come out ahead by investing; you would be better off to spend a smaller amount of money now.
I don't know where you are in the world, but where I come from, you cannot get a guaranteed investment that pays 2,75%. So there will be risk involved; if the next year is a bad one for your investment, then your investment losses combined with your withdrawals for your car payments could empty your investment before the car is paid off. Conversely, by skipping the 2,75% loan and paying cash for your car, you have essentially made a guaranteed 2,75% on this money, comparatively speaking.
I don't know what the going rate is for car loans where you are, but often car dealers will give you a low loan rate in exchange for a higher sales price. As a result, you might think that you can easily invest and beat the loan rate, but it is a false comparison because you overpaid for the car.