I was in Munich last Thanksgiving and did what you want to do. I also did some research ahead of time and then once in Munich.
If you are driving, I guess you can go anywhere. However, if you aren't driving the L; oh sorry that's are version of the tube, subway, transit train, whatever you guys call it; is the way to go. I only found 3 dealers around Munich that are reasonably accessible by City train.
1 didn't handle much and was the most outlying. The other wasn't bad, handled a fair amount of stuff but wasn't very train convenient. I settled on SeeFelder at Zeppelin str. 11. It's listed in the directory of dealers.
THE STORE:
Nice good sized store, they handle lots of stuff besides Festool. Really nice store to wander and look at stuff. If luggage weight costs weren't an issue I would have bought a ton of odds and ends and left broke. Left fairly broke anyway. Great Festool display and demo area. Lots of Festool stuff, stuff you don't normally see, at least not me. I've been to a few Festool dealers in Germany and this was the nicest one. They have tables set up to drill holes, cut stuff with the Carvex and just go ahead and play with the tools. I spent at least an hour + playing with tools, talking with the sales guy etc. Had a good geeky tool time. Store guys were real nice and had no issue with letting me play. They we also willing to wheel and deal on pricing the more I bought.
I would definitely recommend this store to stop and shop.
GETTING THERE:
You can catch any City train from downtown to one of the main transfer stations to get onto the train that goes to Garching. With figuring out which train, which transfer, etc it should take about 45 or so minutes from downtown to the station where you get off as a straight run. Before going out to the Festool store I stopped by the BMW Museum for a while. The train station is right next door to the Museum so it was an easy trek to both locations. Getting to both are different train lines though so you have to back track a few stops from the BMW location to a transfer station for the Garching train.
I'm sorry I don't remember which station to get off at for the Festool dealer but it wasn't hard to figure out. I think I did it on my IPhone while riding the train. It's way on the outskirts of town, in the suburbs. The scenery is pretty cool during the ride. You'll see the big indoor dome stadium thing. The station is 1 or 2 stops after that. Once you get off at the station, go up the ramp/stairs and cross left over the bridge so you are going over the tracks, walk over to the main street intersection and walk a couple blocks past the BMW dealer down to Zeppelin street, turn left and walk down about another long block and a half to the store. I don't want to get to specific about left or right because I could be wrong and don't want to screw you up. I timed the walk, think it was about 12 minutes or so. Nice little walk, semi open, semi residential, semi light manufacturing area. The walk shouldn't be an issue. You may be able to get the guys at the store to drop you at the station if you are loaded up. They offered but I like walking.
My wife went to the Spa, I went to BMW and a Festool dealer. We both had a great time.
Oh, and I almost forget, they did NOT have the router bit set in stock. Sometimes they do, sometimes they don't. I was also looking for that set. They said I can call and pre-order anything I want ahead of time and they will have it for me when I get there.
Hope that helps. Markus