These micro racer cars are sold under many brand names, and most come with a clear sphere to demonstrate this centipetal accelration phyenomenon.
From Amazon: BUY NOW: Micro Racer + Sphere
Micro Racer in a Glass: This tiny battery powered car overcomes gravity through centripetal acceleration and slight friction with the glass surface. With sufficient velocity the surface normal force supplies the centripetal acceleration. The car’s battery last for many minutes and is USB rechargeable.