In the context of a motion to reopen, the Ninth Circuit has determined that car failure, on its own, is not necessarily an exceptional circumstance that warrants rescission of an in absentia order of removal. The Court was very careful to narrow its holding to the facts of the instant case.
"[M]echanical failure coupled with decisions to leave insufficient time to account for routine delays and to pay for car repairs instead of transportation to court, does not constitute exceptional circumstances."
The full text of Arredondo v. Lynch can be found here: http://cdn.ca9.uscourts.gov/datastore/opinions/2016/05/27/14-71907.pdf