Eli crashed Morty in Drop the World (2) because Clare said that she didn't like him.
Morty's owner is from Newfoundland. Epitome rented or leased it from the owner and returned the car after it was written out of the show; this explains both the fake plates and the offscreen crash.
Morty is the second car to be vandalized, the first being The Love Mobile.
The crash occurred offscreen, so the actual car was not demolished.
In-series, Morty did not get repaired and was likely totaled completely, its' front sheetmetal being unique to the professional-car chassis; even if a normal 1962 Cadillac sedan, coupe or convertible could be found as a donor car the needed parts wouldn't fit.