In trying to get my mind off a week of unpleasantry (family wedding, yikes), I'm ordering and planning to install a VDO boost guage in the 124. I've chosen the ashtray as my location and I'm going to T into the pressure line going to the ALDA. My questions are:
-What's the simplest way to run the tubing through the firewall and out of the ashtray opening where the back of the gauge will be?
-What's the procedure for hooking up the lighting? Don't have much experience with wiring, but I'm assuming it's fairly straightforward.
-I'm ordering from Egauges ... do I need to order anything other than the gauge (30PSI Vision Chrome)? I have the tubing and T connection.

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)