Yup regardless of where you mount the Solo, the GPS will work as long as it can see the sky.
In terms of accuracy, I was told that AiM ran a test against magnetic timers during a pro race and the lap times recorded by GPS was within just a few thousands of a second accurate (<0.00x sec). This should be more than good enough for track day/club racers.
Here is more info:
http://m-world.us/aim_solo_dl_gps_la...ta_logger.html