JFK - Car Hire Waiting times

Can anyone help me here. I'm trying to find out the average time it takes after collecting your luggage and getting through immigration at JFK airport to actually driving out of the car hire place in the car hire.

Ideally it should only take a few minutes but I've been in situation were I have waited 90 mins+ after waiting on shuttles and then in the car hire shop itself.

I'm trying to establish if it would be quicker getting cab to Manhattan and then train to Philadelphia or driving direct. I know the drive will be qiuicker but not if I've had to wait too long to get the car.

Any examples?

[FONT=Arial, Helvetica]FROM JFK AIRPORT, NEW YORK TO PHILADELPHIA[/FONT]

[FONT=Arial, Helvetica]The JFK Express:
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[FONT=Arial, Helvetica]The JFK Express has a bus service (the bus is blue and white and can be found directly outside the airport) which will take you directly from the airport to Penn Station.

[/FONT] [FONT=Arial, Helvetica]From Penn Station take the train to Philadelphia. Trains run on a regular basis and reservations are not necessary.

The cost of a train to Philadelphia is approximately $45.00. The train can leave you off at Temple University Station or Center City. The number for JFK Airport Information is (718)244-4444. The toll-free phone number for Amtrak is 1-800-USA-RAIL[/FONT]