Video: The most exciting vintage race car to buy? Try something from the Brass Era.

I've seen some Model T racers for DIRT cheap lately.

unfortunely there aren't any event in the USA that feature them, it's mostly a UK scene

I've seen brass era cars racing at the Watkins Glen Vintage Grand Prix, although I'm not sure what rules/class they run under.  Nothing is jumping out in the SVRA race groups on the website.

These are always great to see. There are too few surviving early race cars, lost to time, wrecks, re-use, and scrap dries.  For more current groups, check out the Ragtime Racers - a group of brass era racers that have fun with their cars, and sometimes tour to "modern" vintage races. And the T.R.O.G.- the Race of Gentelmen, which races pre-ww2 speedsters and some earlier cars on the beach at Wildwood, NJ. and a few other events. 

There's something incredibly pure - and innocent - about these race cars. They're also incredibly wild to watch. There are a few events to see them run. I'd imagine the Chattanooga Motorcar Festival will have them run again.