Dollar - Dollar Express Mystery

I am shopping for a car in Las Vegas for two weeks. I find a great rate on Dollar of $313 all up. I the log in using my (rarely used) Dollar Express number, and behold, the rate come back at $334.

Any suggestions as to why?

not sure if you're preferences are stored and maybe there is some option that's automatically being added to the fare.

With hertz, my #1 Gold number is associated with my company contracted rate. Unless I explicetly change it, I generally get a higher fare for the same car.

the other item is that most companies use flexible pricing depening on how you get to their site/rate. If people use a link from a spam mail to reach a site, they may very well give a different price than a person that just clicks though the site and happens to reach the same product.