They stopped making the Galant in 2012(if memory serves). Dollar does not keep their web site current.
I really cannot give you an ubiased opinion as I worked for
Alamo/National and like them. I like the fact that you can have an additional driver for free if you join the Insider's program with Alamo, you can select your own car, you can use the check in online if you don't have a coupon or additional driver or the kiosk in the terminal if you do have a coupon or additional driver. If it is only an 8.00 difference, regardless of my bias, I would go for the one that allows me to select my car. It would not be fair for me to comment on Dollar as I have never used them, I have, however, read their requirements for payment, additional drivers and I was less than impressed.
http://www.dollar.com/AboutUs/GeneralPolicies.aspx
Alamo does not put a hold on your card, you can use a debit card without them running a credit check on you (you do need proof of a round trip/return travel). These are little things that don't bother a lot of people, but, they bother me and that is why I would not use them.