I don't think you have a choice but to pull CO2 back that has already made it out, or is about to make it out, because we are not overnight shutting down all the coal plants.

A car produces about one pound of CO2 per mile. There is no problem with collecting the CO2 in the tailpipe, but one might easily end up with a trailer hitched to the car for carrying all this CO2 back to the filling station. The gas burned from a 15-gallon tank would fill up five 60-inch-tall gas bottles.

My personal view is the true long-term storage is mineral carbonates, which is some form of accelerated weathering.

Klaus Lackner Quotes