i have a 1 and 2 and 2 black 3's. the 1 and 2 are for sale. i think i have a 64gb class 10 micro sd for sale too.
i have a micover on one of the doors -
http://www.amazon.com/dp/B00533YQVI/?tag=tcg21-20
i've put crazy yarn all over one to break up wind noise before too. supposedly the 3 handles it better. note that whatever it hears it is going to amplify so if you've reduced wind to low wind it is still going to sound rather windy because it will just push up what it can hear to my understanding. so if you have something much louder then you will get better audio as you will capture the loud thing vs. the wind noise (or less wind noise with a micover.) example:
[youtubehd]N6X34OLuY3g[/youtubehd]
the audio from driving is from the external camera; it is picking up engine noise and tire squeal (and wind still) (gopro 1)
kart is loud so it comes through too
[youtubehd]CzrqxiQPOKo[/youtubehd]
vs. older vid just top of car - not sure if micover but it wouldn't have mattered - it is just hearing wind anyway. actually i believe this is no micover but it does have a ton of fuzzy yarn around it. also gopro 1. note the absence of tire squeal; you can actually hear it it's just barely audible though. ie 5:18.
[youtubehd]goLIRh19f5A[/youtubehd]
i have never done an external mic. you need a case with the opening then to run it somewhere, could be good but i'm happy enough with what i've got for now. if it was exposed to a windy area you'd still want some kind of micover on it.
re: light probably later software revisions help and i think the gopro 3 is supposed to handle this the best; low light is always rough though.
i ended up spending the money to buy RAM mounts for 2 gopros plus my phone.
http://www.rammount.com/
i have harry's lap timer for iphone but haven't actually used it yet. data collection in prior vids was done with racecrhono and an old nokia. i merged with video in dashware. multiple cameras were merged in premiere. obd data is bluetooth obd2 reader obdkey. there is one blessed for iphone and i'm wondering if i should switch if harry's ends up supporting it better. also might upgrade gps to something they may have coming. i have a 5 hz external bluetooth puck and a 10 hz one although the 10 is less accurate with no dgps; i have only used it once and some of the sessions weren't really renderable. note harry's lap timer can do some video merge of data for you. but only single cam; and that cam is iphone cam or wifi gopro (not sure what quality maxes out at - i think bandwidth is an issue.) the rotax vid above with very finely updated data is mostly from the mychron on the kart. nice, but my setup is inexpensive and i can hop from car to car and carry it.
some other vids:
rainy gingerman, audio from windshield mounted gopro 2
[youtubehd]blp3fcG8jG8[/youtubehd]
rotax rental race at michiana (funsies)
[youtubehd]Waapymy0xqY[/youtubehd]
road america track inside the carousel, work event i organized
[youtubehd]gjBZLzxoZKg[/youtubehd]