Sandbagging in drag racing refers to adding weight (bags of sand) to your car, racing and losing so everyone sees your shit performance, then after they all think you are an easy target to beat, you discard the sandbags and take them off guard for a kill.
Rags you do exactly what I have done, analyze and emulate my troopers setup after getting flogged with what I thought was tough. Often the teams I lose to are because of AI boost, not my talismans. Then I look at my defense, running exactly the same team, and a player I lost to has multiple gold badges as they lost repeatedly to me when they were driving and I had the AI boost. Last weeks event forced me to play into top levels and run against all the familiar names and this was the case.
Now I can return to my 1 a day arena fight for daily reward and not get stressed trying to outsmart a rigged AI boost situation, arena is not giving adequate rewards to be worth my effort.