Is this the movie you refer to? Maybe?  THis blurb is from vanagon.com...

Chuck Norris' The Delta Force (1986) has a Vanagon at the airport while Chuck &
          co. are planning on raiding the plain to free the hostages. There's
another scene where
          Chuck and another guy end up in Lebanon in a priest's bread-loaf VW
bus with a big cross
          on it. It ends up being a chase / shoot-em-up scene which was totally
unreal. Bullets flying
          everywhere. He's shooting out the back window while being chased by
jeeps. Through the
          wonder of film, Chuck shoots straight while the bus bounces down
steps, over curbs, etc.

Steve Arbaugh wrote:

> Speaking of movie chases, maybe someone out there can help me out: there's a
> movie out there that has a chase scene with a bus painted as a red cross
> vehocle or something, white with red crosses on it. They get chased up and
> down streets, stairs, guns shooting at it, the whole bit. The (foreign) city
> this takes place in was in a war or something and the guys in the bus were
> reporters I think. I thought it was "The Year of Living Dangerously." It
> wasn't, but it's been so long since I saw it I have no idea what it was. I
> know there's movie buff's out there. Any ideas?
>
> Steve
> '85 westy (no bullet holes)
> kent, wa
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf Of
> James T.
> Sent: Friday, January 04, 2002 1:53 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: fry-day fun - movie car chase scenes
>
> Ok, I really liked Bullitt, but I got a betamax tape last week (remember
> them?)
> of Charles Bronson in "The Stone Killer." Awesome car chase scene at full
> speed - not speeded up film stock. Howsabout a 50+ foot burnout from a big-
> block dodge? Smashing into railroad tracks and getting the car airborne?
> Lots
> of blue rubber smoke! This movie has it all. This is the best - as it is
> real -
> car chase scene (Bronson is chasing a motorcycle) I have seen. Check it
> out!