Holder, who is in Europe, said it was a privilege to be asked by Murphy to drive the car.
The Mount driver was pleased to finish seventh at Rally Coromandel last weekend in an older car that he'd worked hard to get ready for the challenging one-day rally.
"I'm looking forward to being back in an AP4 car with Jason. We know the Barinas are still in development and that Josh Marston and the RDL Performance team have been working hard on the cars all season," Holder said.
"The Waitomo-based event is going to be a big day where reliability will be the key."
Holder and Farmer will test with the Penny Homes Holden Rally Team immediately prior to the Waitomo event on October 14.
Holder's rally campaigns have been backed by Vehicle Inspection New Zealand (Vinz) for the past two seasons and Vinz chief executive Gordon Shaw is happy to see Holder enjoy the chance to get behind the wheel of one of the newest rally cars in New Zealand.
"Vinz has been supporting David Holder for the last couple of years and it is great to see the current New Zealand rally champion get the opportunity to drive in an AP4 car for the last two rounds of the season," Shaw said.
"Thanks to Greg and the Penny Homes Holden Rally Team for giving Dave this great opportunity."