hello son members
i have two brand new Qstarz GPS lap timers. these things are awesome they basiclly gps your position every tenth of a second and then display it on a laptop screen to see exactly how your driving on any race track, drag strip or whatever your driving on. you can then sync your gopro video with it and get real time display of yourself laping around a track and where you can improve. id suggest researching all the cool stuff it can do here
http://racing.qstarz.com/Products.html.
The kijiji ad and pics are here
price is $200 for BT-Q1000eX and $400 for LT-Q6000 color