Enterprise Rent-A-Car again offers rental cars for $9.99 per day (for up to 100 miles per day) on most weekends at most neighborhood locations. (Airport locations and select metro areas are excluded.) It ties our June mention as one of the best weekend discount we've seen from Enterprise. It applies to economy class cars rented on Friday or Saturday and ending the following Monday. Of note, fees, insurance, and taxes are additional and may be substantial. Deal ends September 21.