What are Boost Feats? Good question.
If you are looking for a way to instantly fill your boost meter, you can do certain things to help you accomplish this goal. There are quite a few but some notable ones I will mention here are Touchdown in which you have a smooth landing on 2/4 wheels after a jump, Terminator which will fill your boost if you smash another vehicle, and Monster MTX which has you landing on another vehicle. Like I said, there are a lot of Boost Feats so play around and experiment, I'm sure you will eventually pull one off. Note that all of the single player modes are also available in multiplayer mode which is really fun. I probably had more fun playing this game online than I did Need for Speed which, again, says a lot. http://naildbiter.com/mwduB