I am using the HF meter (which is now on sale for $23 in-store...I wish I could justify investing in a couple more). I tapped a fuel injector wire right at the injector and extended it into the dash, which is where I attach the positive lead. The negative lead is grounded at a power outlet.
What do you mean when you say "tapped?" You spliced something into the wire?
Yup. I used a 3m Scotch-Lok quick splice and ran a new wire from there to my meter.
It's necessary to be careful with these, as they've been known to cut wires even when you use the correct gauge connector. In my experience they don't excessively damage the wire but they really have a bad reputation for it.
You know, I totally forgot...while I quick-spliced the wire in my truck, I did a totally non-invasive tap in the VW. I unplugged the wire from the injector, stuck my wire end into the plug, and re-plugged it, effectively jamming the wire in there. I've used the same strategy successfully with fuses and relays in my truck to modify lighting behavior.
If you're already going to strip an inch of insulation, might I suggest using solder paste and then reinsulating with brush-on or spray-on electric tape (or Plasti-Dip)?