The other day, [some idea] was "modify a remote-control car to launch fireworks/firecrackers."
I done did it

The Jeep itself has had the plastic decorative covering (a red "Jeep Grand Cherokee") removed, and replaced with an aluminum tray, to protect it from burning things, and a "trunk" to store and protect its electronics.
That aluminum, incidentally, was the extra stuff leftover after using a measly 4 square inches or so of the giant pieces of aluminum that I had to buy from Lowes, for lack of smaller sizes, to reinforce my crossbow.


The remote has the internals of another remote control car's remote integrated into it, and wired such that the two buttons on either side of the remote will cause the car's motors to turn... or would, if the motors were still connected. A switch in the upper-left turns the ignition remote on or off, and a LED lights up green when the circuit is active. The center red LED lights up when the car is active.

Inside the Jeep's "trunk" are the internals of a second remote control car. 6 AA batteries power the receiver. In place of the car's motors are transistors which, when activated by the buttons on the remote, allow current from one of the 9 volt batteries to flow to the alligator clips. The orange LEDs light up when the corresponding side is active. To ignite things, usually a model rocket's "electric fuse" is clipped in them.

[Cue Music]

Now, I don't have any fireworks yet, but you can watch a video of it just burning the igniters here
So it's a modification and an integration... just not of a Nerf gun.
However, because the buttons on the remote power the alligator clips, ANYTHING electronic can be mounted and controlled on the Jeep... like that Skeet shooting nerf gun. Heck, a small motor to pull an RF20's trigger could be mounted...
