We always jack them up and check all 4 corners after each ride too. I found one of the Tie Rod nuts on each of our cars was getting a little loose.
One stayed tight for 3 races, the other had a loose nut just after 2 races tho.
On our pre-race check over, we did find one loose nut on a shock and one of the cars was also a little low on coolant too.
Have Fun out there!