Why is my 1999 Audi a4 rattling, shutting off when i slow down and leaking coolant?
I recently went to a Midas auto repair shop with the same complaint and they said I needed a new air flow meter, and a spark plug tune-up. I had the work done and for about 2 days it was fine, but then it started to shut off again when I came to a light or stop. Also, my coolant light indicator keeps going off and when i look under the hood it is low. I would say I am refilling it every few days. Sometimes there is a little puddle of liquid, but what i want to know is if the issues i have are all related and what exactly i should do about all of it.

The engine isn't overheating (as far as I can see), and also when I turn off the a/c it stops shutting off at stop lights or when I slow down.

Thanks for all and any answers! It is greatly appreciated!