Leasing or financing

Good tomorrow’s forum community. I’m in a kind of mess. In our household are an 11 year old Seat Altea Freetrac 170 Diesel-PS and an 18 year old VW Polo with 60 petrol -PS. Both have about 168,000 km. We would like to buy at least one new one. Are to consider whether it should not be a factory newer. Because there is still a guarantee and no repair costs. It should be a Suv with four wheel, because we need 4×4. I think, since I have a used also financial I can also buy a new one, which I return shortly before the warranty expires. Leasing is cheap at the moment, only horrors me possible follow-up costs at the return. In addition we have eon little child and whether we can give the car back 100% so is questionable. I heard and also read that financing would be better. There you can give the car back too. Now I have a few questions. Must, if you return the car the closing rate paid we rden? What about the deposit at the next vehicle. Will the first vehicle be charged? A (VW) dealer explained to me years ago that the vehicle can be financed up to the final rate. Then either pay the rate, continue to finance or fetch new ones. If that were so, I would tend to lower the rates for a higher final rate. Is it also true that if you can get financed higher discounts? Every dealer says something different, just to sell his vehicles. Ahja and another question. Does this happen with EU vehicles exactly like this? Thank you in advance Greeting Christian