Sam, I have these gauges in my bug, and they work fine. The speedo hooks up to the front wheel via the cable that you use already. No change, it just screws in and picks up where it left off. The rev counter is the same as any other rev counter and only requires 3 wires. The idiot light/fuel gauge/temp gauge cluster is easy to wire in once you've figured out what colour wires do what. I can help you out there with an explanation once I've checked mine (can't remember off the top of my head) The clock is just a clock, it requires a constant live and an earth, the oil pressure gauge works fine with a VDO pressure sender (not just the idiot light switch), the ammeter also works fine, just plumb it in. I haven't got it hooked up yet as I haven't got a sender for it yet, but the water temp gauge from the 944 should work okish with an oil temp/cyl head temp sender. If not, I'm sure a 52mm VDO gauge could be taken apart and fitted in place of the water temp gauge, all the little gauges seem more or less modular. The fuel level gauge I can't vouch for yet, accuracy wise. Again, i haven't gotten round to getting and properly wiring up a fuel level sender so I can't say. Again, I reckon the module out of your original VW clock might swap into it though...
It's all VDO stuff, and so long as you use VDO senders you should be OK.
Fitting all 6 of the gauges into your dash though... I'll leave that up to you!
