The billboards are definately part of the themeing, its a car chase through the city, have you seen the movie there are billboards everywhere. In fact one billboard is the reason why they are able to blow the truck through the road because the helicopter flew behind it. Also tunnels are way better when it is pitch black, I once rode IJ and there were lights on in the tunnel and it totally ruined the effect. Also I dont see how you can over look the parking structure, the cop cars, the tiled wall going down to the subway tunnel, the tunnel, and the water splash at the end as not being "themed parts of the ride." Personally I think the ride is very well themed.