Please use the smartphone app to post rideshare/carpool searches.
This would help in getting all posts oragnized and consolidated in single place and matching results would be more meaningful.
Among few good apps I found RS4L (RideshareForLess) the very best.
On IOS http://itunes.apple.com/us/app/ride-share-4-less/id490880546?ls=1&mt=8
Go ahead and download for free and start saving on gas/time.