My wife used to work for the largest advertising agency in America called BBDO, and the ad agency has absolutely no control over what the customer (Geico) wants to do. All the ad agency does is come up with advertising ideas and gimmicks, and the customers either approves them, or says no, and a lot of times the customer will come up with an idea and give it to the ad agency have them run with it.
Geico is owned by Berkshire Hathaway which is basically owned by Warren Buffett. If Warren Buffett/Berkshire Hathaway didn't believe "drunk rednecks driving beaters" were a market they wanted to be involved in do you really think they'd be in NASCAR? Warren Buffett/Berkshire Hathaway also owns "Fruit of Loom", and if you remember they used be associated with Robby Gordon for years, so obviously Warren Buffett/Berkshire Hathaway think the NASCAR crowd is a crowd they can make money off of, or they wouldn't be involved in NASCAR.