OK, I'm sure a lot of people know about this, but I'm posting it because a quick search of "Crashin Racer" didn't turn up any results.
It's very simple actually;
Step 1) Target desired mob. (/tar or whatever...LoS doesnt matter)
Step 2) Use your Crashin Thrashin Racer
Step 3) Dismiss your Crashin Thrashin Racer
Step 4) ???
Step 5) Profit.
A tip, do NOT test this on curator. If you still want to let me say "I wanred you lol!"