You name the car and use the camcreate command. For example
bomb1 = "shell125" camcreate getpos myturbominicooper
or in as script you should use a local variable to name the shell. For example
_bomb1 = "shell125" camcreate getpos poorbastardscar
if it's for multiplayer you must tell ofp to only create the shell on server, otherwise there will be so many shells as there are players. For example
Insert a gamelogic and name it as server. then in a script
?!local server: _bomb1 = "shell125" camcreate getpos turbomegascoda
or in a trigger
condition: !local server
on activation: bomb1 = "shell125" camcreate getpos fordsierrarules