An important thing Mike's bullring oval shows is that when it comes to racing an oval is often elliptical, or egg shaped. I made my oval using wood sections patterned after plastic track, not taking into account the way racing lanes actually flow around a real track. Indy (2.5 miles around) is a rectangle with round corners, but bullrings are more like elongated circles where straights and turns meld into each other. Mike's track looks like what a bullring should be - both for realism and for ease of driving by softening up the entrances and exits of turns.
Slothead