Hi Erick,
if you want to explore munich by night to have some drinks, then the "Platzl" ist a good place to start.
http://maps.google.de/maps?f=q&sourc...,0.008234&z=18
You will find a lot of bars and clubs around there, the Hofbräuhaus and you can achieve anything without a car.
In my opinion the trip from Munich to the Ring on an Saturday is a challenge.
I hope you won't have to many tourists on the road.
Greetings from Munich!
Tobi