Take a look at the sentence again:
When Robert is riding his Honda motorcycle, he drives recklessly, weaving
dangerously through rush hour traffic, Robert doesn't
care that he might leave a kneecap or chunk
of thigh speared on a car bumper.
No punctuation of any kind is necessary between care and that. Robert doesn't care is a main clause. That he might leave a kneecap ... begins a subordinate clause that must be attached to a main clause. Generally, when a subordinate clause follows a main clause, as in the example above, you need no punctuation between them.
Go back to the sentence to try again.