looping – but need muscle cars… https://afxracing.com/product/loop-track/
basic build ‘n race 4.9 meters has the loop!
https://www.carreraslots.com/slot-cars/CGOCars.html – additional cars to go with it that aren’t lego style.
Above is link to the big catalog explaining the differences. the 4.9 meters is the only one with the loop… it also is nice since it’s small enough to fit in 5 foot table area.