Which are the best used pickup trucks?

I signed up for a new program with my insurance provider to help me save, requiring me to plug a little device into my car’s OBD port. I’ve looked all over and can’t find it: can you tell where a 2016 Audi A3’s port location is?

I’m trying to decide what type of used car to buy. I was considering the Lincoln Town Car, but I’m not sure if it suits my needs. I drive for Uber near the airport, and I get a lot of passengers with small mountains of luggage. I don’t know how much I would be able to squeeze into the Lincoln Town Car’s trunk. What’s the trunk size of a Lincoln Town Car?

I love pickup trucks but don’t love that they’re major gas-guzzlers. I was looking at buying the smaller Chevy Colorado—what’s the gas mileage like on it?