A lot goes into making videos of racing action. The car or motorcycle has to be fast. The driver has to be highly skilled. The video camera has to show something exciting, not boring. The video quality must be very good so it captures the nuances of rapid-fire situations on the track. All of these things must come together when producing great racing videos.
So where can you see good examples of high quality racing videos? People normally go to the huge video mega-sites as their first stop. The problem with these is that they are open to everybody and 7 out of 10 videos are pretty much amateur garbage. That's not to say you can't find great content -- it just means you will need to spend a long time finding great content on these sites. Other sites open to the general public have this problem, but they tend to do a better job of controlling the quality or they are more focused on a particular motor sports niche and have less random content.
One place to look is the action camera sites. These guys have a vested interest in selling high definition cameras you can mount on a helmet, roll cage, or roof of a car. On board action cameras have revolutionized the production of high quality racing videos, allowing teams and racers to replay their actions and what they experienced on the track, study it, and learn so they can become great racers. The camera makers' sites themselves always have a range of latest videos which are exciting to watch, but are essentially advertisements for their products. They are extremely high quality but you won't see a large selection of on-track videos on these sites.
Other places to look are video filtering sites. These are dedicated search services for racing videos. These site are starting to gain traction with motor sports racing enthusiasts. You sign up for a website or email service and you get a bunch of "top picks" that cut through all the garbage and save you a lot of time.
Finally, you can search on motor sports forums. There are hundreds of these forums for auto racing, motorcycle racing, truck racing, drag racing, and many other types of motor sports. You can find some great gems in these forums -- usually one or two videos hosted by archivists, historical sites, racing teams, or racing fabrication shops. These sites are for true enthusiasts and shouldn't be skipped!
These are just some ideas to help you find exciting racing videos. Hope you enjoy!