Blaupunkt was probably a sponsor, or perhaps the hosts just use a Blau tent. Until recently, we were using a Bazooka tent and now we are using a Focal tent, and we are not sponsored by either.
It's impossible to accurately guess what you will hit. You'll just have to go and see what you hit. Don't worry if you don't get a high score, just learn from the experience, tweak your box, tweak your electrical and give it another try. Look at everybody else and see how their systems are configured and talk to as many people as possible, make some friends and try and pick up some pointers. Enjoy the experience of the competition, don't just go to try and win. There is a lot of fun to be had and a lot of experience to be gained at a show, make sure you take advantage of it.
As far as what to play, try and get ahold of a CD with a sweep on it, between say 20-80hz, or 20-80hz, or whatever range will best cover the lower notes. If they are using a Termlab, you can run the sweep and they will be able to tell you what your loudest frequency is. If it is a smaller show, see if they will let you do a test run before the competition starts to find your note, or ask them about it when you go do your qualifying round. My advice to you is once you find your note, play it only once during your run. Pause the track, set the track, set the volume, and unpause when you want to do your burp. If you can run your car, hold your RPM at 2,000 until the last 10 seconds or so, and THEN that's when you burp your car. You will get a better surface charge on your battery that way. Don't play your car between rounds, you will just heat up your gear and drain your battery.