Originally Posted by glostix

I hear you, also a car lover and take my vacations expressly to rent a sports car and drive mountain roads for a week straight.
I don't know any programming, but if you have some basic skills you might be able to use a website scraper to collect the data for you, it can be set up to run however frequently you like (as long as the rental agencies don't autoblock your IP for pinging their servers too much). In short, you'd be reverse-engineering another AutoSlash/Priceline or something, and that's probably a lot of work.

There was a Quora thread where some programmer basically did this on a macro scale and found that weekend rates are cheaper, last week of the month is cheaper, and that the companies are all about the same except bottom dollar/horrible service places, and National which was better service.