I wonder if you could drill a hole in the back of the intake manifold and run a line through there, back where nobody could see it, then have the spray bar/nozzles and all the fittings be internal, without messing up the airflow too much.

 

Ive seen an entire fogger system plumbed on the bottom side of a big block chevy intake.

 

When I first had just a single stage dry shot it was COMPLEATLY hidden. Even knowing I had nitrous it would be hard to find the evidence.

I mounted the bottle under my bed under the passengers side step. I hiding the solenoid really isn't that hard. Just put it out of sight. I ran the line from the bottle to the noid inside the frame. From the noid to the intake track I ran a short line to a fogger that plugged in to a hard pipe just after my filter. I have a hardware store intake so it was easy to mount it under the intake. Stock intake would be even easier to hide it in. I put some loom around the line and made it look like a factor smog line. I made a LOT of money of ricers with my set up. Now I have a two stage and there is really no way to hide it. The bottle is still under my bed.

 

I'd hide the lines inside black split wire loom, and get the Escalade (or simillar) 3 pc. engine cover set. Most of the stuff can be hidden under them.

 

we just did a setup on a buddy of mine's Mustang... we put all the noids in the fender and covered all the lines in loom and vac hose.... the nozzle coming into the intake is covered by a piece of radiator hose... VERY sneeky.. the switch panel is hidden in the ashtray...