The In-Laws (1979)? Haven't seen it.
Sorcerer (1977)? Not it.
Polk County Pot Plane (1977)? Haven't seen it
The Cat from Outer Space (1978)? Not it.
Scanners (1981)? I don't remember an armored car in it.
1990: The Bronx Warriors (1982)? Haven't seen it
American Ninja (1985)?
Invasion U.S.A. (1985)?
Heartbreak Ridge (1986)? Haven't seen it
The Delta Force (1986)? Haven't seen it
Hands of Steel (1986)? Haven't seen it
Thunder Run (1986)? Haven't seen it
Double Target (1987)? Haven't seen it
Tango & Cash (1989)? Haven't seen it
Harley Davidson and the Marlboro Man (1991) Haven't seen it
"Incident at Crystal Lake (1985)"?
Danger: Diabolik (1968)? Not it.
"Detour to Nowhere (1972)"?
Firepower (1979)?
Uncommon Valor (1983) Haven't seen it
Extreme Prejudice (1987)? Haven't seen it
Fighting Madam (1987)? Haven't seen it
Dead Presidents (1995)? Haven't seen it
They Came to Rob Las Vegas (1968)?
"Sky Bandits over Hazzard (1984)"?
Looking over the other ones as time permits.
I want to think the story was set in the US and the hijack took place near the beginning.