Do a good wash, and wax. Wax is a protective coating- do this every few months and it makes cleaning quick and easy, as well as protecting the paint. Every time you do it it's like putting money in the bank, a car with good paint looks like a nice car, and people pay more money for a nice car.

Buy a little bottle of rain-x. Read the instructions. Do them twice for the first go. It makes an insane difference for your vision when driving in the rain, and driving in the rain is when you really need to see.

Learn how to change a tyre before you need to do it. Figure out how the jack works, and where you need to put it under the car so you don't damage anything.

Don't trust your drunk self. The cost of a taxi home and back to your car the next day is way, way less than the cost of having to live with the fact that you are responsible for the death of someone's child. Don't give a shit if you feel fine. Give your keys to the barman if you when think you might try and drive.