Boxhead, I've been experimenting with GoPro cameras for a while (HD2 version) and I've found their onboard microphones and pre-amps to be absolutely terrible. I ordered a cheap mic (see below) and the foam windshield which is also in that listing, easily a 100% improvement in sound quality and it allows you to locate the mic down in your footwell in still air so you don't get any static. Mine took about a week to arrive from the UK.
BINAURAL STEREO TIE CLIP LAVALIER ELECTRET MICROPHONE | eBay
You'll need the skeleton back door to allow the mic to be plugged in. I also wear the WiFi remote on my wrist so I can stop/start remotely without fiddling with the mobile phone app. Always try to record in the highest FPS you can - in your case 60fps for 1080p or 120fps for 720p. This results in better video in environments where there is a lot of vibration or very fast motion. Lastly, I always use Protune mode as it provides better contrast and higher bit rates (less artefacts) but it almost doubles the size of your video files - decide for yourself whether it's worth the trade-off. Oh yeah, grab a spare battery and/or an adapter for the cigarette lighter to allow USB to be plugged in.