Hello Negril Salute...You could find a private driver to take you the "back way" to Negril .Theres a turn-off in Mobay that goes thru the interior vs. the usual coast route.. I'm sure you'll have no problem finding a driver to accommodate you...
FYI- i;d take the free transfer from Ochi to the airport then either have a pre-arranged driver meet you there (my suggestion) or negotiate with a driver at the MBJ airport..