What do you think will happen to auto racing in the future? Personally I don't think it looks good due to the more globalized effort to reduce carbon emissions into the atmosphere. The drivers in the top series seem to have lost their personalities the most compared to other sports since big sponsorship money started coming in. The cars are for the most part much safer now compared to the past. Proof of this is there hasn't been a death in a Sprint Cup race since Dale Earnhardt died in the 2001 Daytona 500, and its been since 1994 that Ayrton Senna died at Imola. This is a great thing for driver safety, but it probably causes a loss of "bloodlust" fans. There are hundreds of other factors, but I think that will become a bigger one in the next few decades. Here is what I think will happen with different racing series:
NASCAR: Originally a southern sport, NASCAR became a more national sport around the late 1980's/ early 1990's and capitalized on the opportunity by expanding its reach and building more tracks nationally during the 1990's. It seemed to peak sometime around 2006, a few years after the sport introduced its version of the playoffs "The Chase." Jimmie Johnson has dominated the sport since the introduction of The Chase, and with colourful characters from the past retiring from the sport coupled with the recession, and the cars becoming more and more alike, has lead to the sports downfall in recent years. The tv coverage of the sport has gone down a bit since the SPEED channel became FS1. It should also be pointed out that less crashes and more "phantom debris" cautions (which generally always help one of the top drivers at a critical time) have turned away long time fans of the sport. NASCAR will probably remain relevant nationally in the USA, but will never be as popular as the stick and ball sports which it competes against for tv ratings, and won't receive much support from international markets.
F1: Considered the top racing series in the world, F1 like soccer has grown internationally and is one of the most popular sporting events globally. However, unlike NASCAR which has outdated technology and promotes parity, F1 has the opposite problem where you know which manufacturer will win each race/ championship based on which team designed the best car, and you can pretty much tell who will win a race based on who leads the first lap. It is starting to overlook its fanbase by having more races in the Middle East and surrounding regions than its historic European based schedule, which causes races to start at inconvenient times for the European and North/South American fans. I think F1 is pretty much at its peak now and will begin to become less popular in the coming decades.
Indy Car: Probably the most exciting auto racing series in the world, but lacks an identity outside of the annual Indianapolis 500 every May. I don't think driver's appearances on "Dancing with the Stars" will do enough to increase its popularity. The death of Dan Wheldon (Justin Wilson's was a freak accident), and Danica Patrick's decision to leave for NASCAR hasn't helped the series. Indy Car has been in a bad place since CART and IndyCar split in the mid 1990's, and I can't see it improving anytime soon.