Remote start isn't hard. Take a good ESC, stick it on channel 3.
Now, get an electric start like the EZ start .15 (I use this on my .28!) or maybe Acme's electric or Losi's. Traxxas's EZ Start for the 2.5 might be a problem (unless you're running a 2.5) due to the shape of the one-way bearing housing.
Now, go to Advance or AutoZone, and get a ballast resistor. The 2-pole one.
Ok, put a Dean's on the ESC's output, and on the other half of the Dean's, solder on 2 wires on each pin. 4 total.
Ok, 1 wire on each side goes to the motor. You'll have to find the right polarity to get it to spin the right way when you turn on the ESC.
On a side note, program the ESC to power the motor in one direction only. No reverse.
Now, take the other 2 wires. Put a glow-plug connector, either the blue Traxxas type, or any of the others out there, and solder it up on one of the remaining wires.
Take the last wire, put a spade connector on it, and connect this to the ballast resistor. Take another piece of wire, put a spade on it, and a loop/eye connector on the other. Bolt the eye to the engine (on the mount bolt is good) and plug the spade onto the other side of the ballast resistor.
Push the ch.3 button. Motor spins, glow glows. Push it again, and it stops.
I don't know how well this works without using a 6-cell 7.2 pack. Perhaps a LiPo would work and still fit in a battery box? but I've tried 6-cell AA (well, sub AA, really) packs and they just don't have the umph.
I installed a switch between the ESC and my RX, just spliced it into the +/- wires, and left the orange or white signal wire alone, I guess it depends on how your ESC is wired. Mine supplies power to the RX and servos.
Now, I know the EZ-start motor doesn't ground to the engine anyplace, but if you have a situation where one side of the motor is grounded to the engine, then put the ballast in-line with the glow plug, and use the side off the ESC/motor that's not grounding to the engine.
The biggest issue with the EZ-start is the motor is a bit small, and on cold days it's best if I warm the engine a bit with some hot air. A blow dryer. Or I just talk at it and it'll glow red for me in seconds ;-)