You can run a power wire in a couple different ways. You can run it through the interior or under the vehicle. To get inside the vehicle, you can either find a grommet in the firewall that is used by other wires, or is unused or you can run it under the car and through the grommet at your spare tire compartment. I've attached an article to help further. view full answer...
You wouldn't necessarily have to use a die grinder to enlarge the frame hole for trailer hitch # C11421 for your 2018 Toyota Yaris iA. But if you wanted to most auto parts stores have a tool loan program. I believe even some home improvement stores are starting to do that too. Otherwise, you could use a file, chisel and hammer, or even a drill.
The size it needs to be is sort of arbitrary. There is a spacer block that goes up into the frame that is about 3/16 inches thick, 1 inch wide,... view full answer...
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