I meant to post this reminder earlier, but it's been so cold here in Jersey I thought it was still winter.
If you don't clean off the card you will likely not get new runs at some point. It's not about the physical capacity of the card - even a 1GB card physically FIT thousands of runs - the RP software has issues around 100-150 runs.
Cleaning off the SD card
In addition to cleaning off the SD card, think about backing up your data (7th item down on right-hand column)
http://motorsportsinnovations....acepak-help-tips.htm