"The engineering side really excited me that you could actually create something that looked like the current cars and you could fiddle around with them," Stokes said.
"We take it away and basically assemble it ourselves. I have a good friend Ian Mason in Nelson, who has built a lot of cars for us now, and he will do the rest of it - putting the engine in and gearbox, suspension and everything else you need in a rally car."
There was the option of buying a purpose-built fully finished R5 Fiesta from M-Sport in Europe but that option is a little more costly.
"It makes it that you can get a fantastic car for what I hope is an affordable price," Stokes said of the AP4 route. "That is one of my real motivations - to prove to myself that you don't have to spend megabucks to get yourself into the current generation."
Stokes is hoping his car is ready for Rally New Zealand in November while Campbell's will be ready for next year's championship.