I've had some luck getting a site into About.com by directly emailing the section Guide (it wasn't travel/car rental).
I wrote the e-mail in true PR style -- helping the Guide with useful information about a site that their visitors might like, and naming the stand-out, unique and newsworthy features that made it worth mentioning in the face of all the other sites in the category.
The site got a short complementary write-up three weeks later that brought good traffic -- a stable link in the section, for free -- and search listing.
The section Guides are basically reporters. They always need good new content to retain their audience, so it's worth a try. You might even get mentioned in their newsletter.
What do you mean by search section? Also, is your site commercial, or just information-based? When I was looking at the sites that About.com includes, it seemed to me that they might just be information-based.
I mean that the About.com page that mentioned this site was a returned result in their front page "Find it Now" search box. A very nice traffic boost while it lasted.
This is an up front commercial site -- all about sales with only a few informational pages. In fact I've been trying to get the client to come up with more information -- it would help a lot for better placement on many engines and directories.