a low budget was mandated: £1000, or about $1275 as of this writing. Teams from legendary racing outfits like Prodrive, Bentley, Cosworth, and even Rolls-Royce entered, but as carbon-fiber wheels and high-performance bearings started showing up in builds, it became pretty clear that budgets were not staying meager. Crashes were relatively common also, even after the course was shortened a good bit. The Soapbox Challenge ran for just five years and now the cars only occasionally appear at the Festival of Speed.