Many Philly downtown dwellers have atleast one car, for weekend use, if not for commuting.

Philly is not like NY, where many from NY live without a car and can really get by without it.

Since there is no NJT service from West Trenton to Newark, it'd make more sense to have shuttle to Trenton Transit Center to capture NJ.

There is jitney service from ACY to AC Rail Line station. It costs $10 a ride, but the jitneys drop pax at the ACY casinos as well, so it's not just for airport to rail station. The distance is 13 miles.

The TTN airport to Trenton Transit Center (Amtrak) is 7 miles, and ILG airport to Wilmington Amtrak's is 8 miles.

Regarding Wilmington/ILG, for a pax, it makes more sense to rent a Budget car and do a one-way (from ILG to another Budget location), if one doesn't have a car. Most of Frontier's service for Wilmington is anyways during the week when Budget is open.