The lifetime of a car is something that’s unpredictable. You never really know. Sometimes a used car that is over 30 years old is better than a car that is fairly a year old.
As for my recommendation, I would suggest that you buy a new car with the money you have saved instead of wasting it on a used luxury car. But if you are adamant on buying, you can do the basic checks that you would do on other cars. Take the car for a test drive first. Get comfortable with it. If you feel something is abnormal, get it checked by a mechanic before buying. If the selling party doesn’t allow a test drive, don’t buy the car.
Check the car for dents and damage. Do the same for the tires. Once you are done, take it out to a mechanic for a sweep of the engines and get it checked for internal problems. Only then consider buying the car. After doing these basic procedures, check the papers of the BMW car and find out the market rate for the used car by going to multiple dealers.
If you need to replace parts after buying, check the cost of the parts. According to my knowledge, BMW part prices across America will rip apart your paycheck if you’re not careful. Last but not least, I would ask you to reconsider your choice of buying the BMW. There are other car brands that are more reliable than BMW. Their concept of ‘sophisticated engineering’ is spoiling cars and not enhancing their abilities.
It’s okay to have a brand new car than to have a bad luxury one.