There are quite a few ZR rally cars about now, Sport 'n' Racing have done a whole scholarship using them in 2004.
Naill is a privateer who is doing the rounds like you're planning to do. There are also a few sprouting up in countries like Finland who are also building up privateer ZR rally cars for this years season.
Many of these people have designed and developed custom parts for the ZR specifically for the motorsport use of the car, and some are even selling the bits on to other people upon request if you need to source some bits.
Take a look at the thread linked in my signature for details of the first rally even this forum is attending in 2005. You get a chance to talk to the actual teams - never know who you might meet :mrgreen: