Here's how I did it for an upcoming short film:
Took a standard coffee can, cut out a 2" hole in the bottom, wrapped light weight foam around a Shure SM57 microphone, and put it in the can with the xlr input sticking out the hole, leaving about an inch and a half of space between the mic's capsule and the open end of the can. The microphone is essentially floating freely in the foam without touching the sides of the can.
I then put two nylon stockings over the open end to act as wind jammers. Originally I wanted to get it under the tail, but there wasn't enough space above the wheel. Instead I zip-tied it to the passenger footpegs and aimed it at the exhaust. In my case, I have an Ex Box, should you have cans simply turn the contraption around.
Amazingly no wind noise or vibrations, nice deep sound, and with a little eq it will sound even better. A coworkers snagged some photos of the contraption. I used a Zoom H4N recorder in the backpack.
I promise I will post the final video with the sounds as soon as it's done in a couple weeks.
Let me add this photo was during a test in a parking lot, I do wear a leather jacket when in traffic.
