Unfortunately disappointed !!!!! wheel falls off, brake loosens ever by itself!

I have the car for my 11 months old son gekauft.Eine full week, we have to wait for the package, but well ...! At last he was there, just unpacked, assembled and adjusted brakes. Visually, the car is a real eye-catcher for small and groß..das wood is massive and beautifully finished! Unfortunately, the link is a bit too high. But that's not so bad, because the small to grow! ;-) What we have but we are VERY annoyed the brakes. We have it set to "hard", as our son can not be so safe on the road. But after some time, the brakes are loose again, which I find very dangerous. I'm always there when son running by car, but if the kids are so alone and the brakes here are relaxed, which is very bad. My husband had the brakes so beautiful readjust desöfteren and yesterday the screw has even solved the left rear wheel while my son was in the car and the wheel has fallen !!!!! That's a No for me! I wish I could send it back, but my son loves the car now dearly that my husband said he repaired that! Oh, before I forget, another drawback is that the car can only go straight. With curves you always have help as an adult! I forgive here anyway 3 stars because the car to look very nice and touching. Actually high quality. But the wheels and the brakes come off is impossible in my eyes and in the price is something else to be expected!