Having been around rallying for all of my 31 years, I can safely say I have seen just about every service vehicle known to man. I have been part of the service crew for most of those years as well. I have learned a few things along the way, so here are some pointers.
1. Look at what you will take before you buy it - I put this at number 1 because it is sooooo important. If you are going to carry 15 spare wheels, an air compressor, a generator, 3 gearboxes, 400 litres of fuel, three kids, plus tow a car trailer, then buy accordingly. Plan for your expected load.
2. Don't bother with trailers. They are more hassle than they are worth - Sure they carry gear, but your average 6x4 isn't designed to carry what you will invariably carry over the crappy dirt roads you will invariably take it. We used one on the '95 Round Australia. Wheel bearing failures, spring hangers tearing off, axles moving - the thing was welded back together 4 times over 3 weeks. It needed more work than the rally car!
3. If it is 2 wheel drive, then make sure it has an LSD - even then, it may not help. Oberon (Take 1) and Bega last year saw me bogged. It did have alot to do with the presence of number 2, but remember where this vehicle could be going. There are always people around to help you, but it is better to not be in the situation in the first place.
4. Remember who will be driving it - chances are you will be in the rally car. Case in point - my better half is driving my service vehicle with the two kiddies in it, and I don't want her to end up in the position that I was in at number 3. That is the quickest way to end anybody's rally career! If it is several of your mates, then they may be more self-sufficient.
5. It should have enough seats for the service crew PLUS TWO - No good the service crew rolling up to your first DNF only to find that they can't get either you or the car out...
6. It should have commonly available parts, or (better yet) share parts with your rally car - Face it, service vehicles sometimes need servicing themselves. No point in looking for a fuel pump for a VW Caravelle in places where people can't even spell VW... How about the bolts? Metric? Imperial? Do you need to carry two sets of tools? How about the wheels? Do you need to carry a spare for it too?
7. Whatever it is, put some time and planning into the cargo area - By building a few boxes, racks and cages you will maximise the use of space and allow quick access to most items. And you can't overlook security. You will not believe how important these are...
If you have read this far, then you may ask what service vehicle I have. When I went shopping, I was looking for a V6 Dualcab Navara 4x4 or V6 Dualcab Triton 4x4. With a canopy and some energy spent on security, it seemed like a practical all-rounder.
I ended up with a RAV4.
You wouldn't believe how influential number 4 can be...
The service vehicle topic seems to be a hotly debated issue, and all concerned have made valid points. The upshot seems to be this - buy what you can afford, and what you will be happiest with. If a Suzuki Mightboy is your idea of the best service vehicle, then go get it tiger! You will quickly discover for yourself what is right and what is wrong for you. Also, with a bit of lateral thinking, you can make most things adequate - even a RAV 4!
Happy hunting!