Im reading through this post and Im beating myself silly. You cant tell me some of you guys are actually using wire caps. What are you installin a freakin ceiling fan in your car!! You dont use those. By far the best way to connect 2 wires if needed, is by soldering it. There are some occasions soldering is virtually impossible. This where you use crimp connectors or spade connectors. Please dont twist 2 wires together, then wrap them with tape. Thats just abusing your car. If you do, I would suggest in buying a fire extinguisher, a big one.