You are welcome.
The promo is on the first page of their website and is $10 a day over a 4 day weekend and runs until the end of May. Bookings for 2 days, 4 days and then 1 day might work out cheaper but you will have to play with their reservation system to find out. Or you could just rent for 4 days and use The Bus, taxi or walk, for the rest.
I have been known to drive VERY slowly in the direction of the airport because I never want to leave.