I am googling "car insurance", "nascar clothes",and "pizza delivery". Most of the page 1 domain name results do not contain either of the keywords.
This is a list of how many domain names contain the search terms that appear in the results:
car insurance: 1 keyword in first page of results.
nascar clothes: 1 (nascar.com)
pizza delivery: 1 result had pizzadelivery, 3 other results just had "pizza"
I also checked that google had indexed "carinsurance.com", "nascarclothes.com", and "pizzadelivery.com".
I would guess page content and linking has more importance in searching. In another thread I talked about the importance just being able to remember a domain name and communicate it easily via offline media. example: happypuppy.com -> a video game site. The domain has nothing to do with gaming but I'll never forget that name. Branding is more important. And, preferrably a brand that actually relates to its topic -> like "flyforless.ca" - makes it easier to remember.
What I personally like about obvious domain names is I often just type them in and see if I get what I am looking for. It doesn't always work, in about 1997 I typed in "kiss.com" because the band was coming to town....but instead I got a website trying to hook me up with Russian brides. But sometimes I luck out and get just what I am looking for, like flowers.com.