Two words Sgt... Warr Anty.
If you skip out on the dealer you may have warranty issues down the road. I've seen on the forum where some dealers are more than fair at 50.00 for service, and some are animals at 300.00 plus.
The service should include all the basics... Tire pressure/oil change/filter check/plug check/valve adjustment/component check (brakes/steering)/safety check (lights,blinkers,horn).
It should all take an hour to an hour, and a half at whatever the shop charges. Adding the pigtail is a 15 minute deal once they are in there so I would go over what they intend to do, and ask them to add the wiring for you.
It's all about the relationship you have w/ them, and if they care about you after the sale.
You pay hookers to leave, and pay the dealer to stick around. Just my opinion.