Voltmeter just connects to any wire in the car that draws power when the car is running, thus the alternator is working. An oil pressure gauge, the best way to install is to use and Oil Filter Sandwich adapter that goes in between the block and oil filter and you have a few holes in the adapter you can plug the sender for oil temp, pressure, or even install and oil cooler feed and return line in them. This site has it for sale and I only point it out because it has a drawing showing you what it looks like, how the connections go in, etc: http://www.rtec.ch/webshop/product_info.php?products_id=137
you can find it cheaper on other sites like PTuning.com. KSPec also sells a Toser oil filter sandwich plate. Same thing, different brand. There's a bunch of companies that make them. If you do a search on the forum for Greddy Oil Filter Adapter you should be able to find a few threads talking about them and what size to get for the Tib.
Also, when wiring gauges, once you get them in your pod/guage holders or whatever you can splice the power, ground,etc. wires from each gauge together and then just tap into one source for your lighting, power, ground etc. instead of multiple wires. This will clean up your install and it will prevent any possible screw-ups. I tapped my power into the clock on the center console. Just be sure you tap into a wire that has power only after you start the car and not all the time. Get a voltage probe that lights up when there's current to test the wires before you splice. A constant power wire= gauges lit up all the time = dead battery.
I'm not sure on the Torque gauge as to where to wire it so I'll let someone else answer that question. I hope this helps. Feel free to ask any more ?'s and I can answer what I can.
Trinity i'm not sure about splicing them all in one. i connected them in such way(but didn't solder) and it goes like this: the upper(the furthest from ground point) is the brightest, the middle is dimmed more and the lowest is the darkest , by the way the oil pressure which is the lowest maxes out its indication on the ignition on setting and keeps in the max position which i can guess is too because of the bad paralleled ground. or maybe it's defective. anyways , i'll disassemble a-pillar in some days and will know the truth.
Hmmmm... that's interesting. I've only got two gauges and I just took the power, ground, and lighting wires from each soldered them together at the ends with a wire that would then go to my OEM wires that I spliced into. They are both working fine and no difference in brightness or anything. Always make sure you've got a really good ground.