Before you rip my head off, please read!
Our household is still a 2 car household. I drive a 2013 Ford Focus and my wife drives a 2005 Corolla. One major need is we have a small boat that needs towing. The boat+trailer probably weighs around 1500#s, which is right about the tow capacity of the Corolla. The logic at the time of when I bought the focus was my inlaws had an SUV that could tow the boat for when we had longer trips and I didn't feel comfortable towing with the Corolla. Unfortunately they sold the SUV shortly after I bought the Focus.
The Focus technically isn't rated to tow in the US. That being said it has more HP,torque, better brakes and ABS than the Corolla. I bought it because I was coming from a TDI Jetta that was constantly breaking and I wanted something shiney, manual and fun. In hindsight I wish I bought an older Toyota Highlander because the Focus has already had a few issues and is depreciating like crazy. I bought it for $12,500 2.5 years ago and it's currently worth like $8,500. It has 38k miles.
The Corolla has been a fantastic car. Almost no issues but the clutch is starting to slip and it's in need of a paint job. My wife has had it since new and it's probably worth $3,500 now. A normal person would probably replace this car since it's older and more beat up but it truely has been a phenomenal car.
What I probably should have bought was a Toyota Highlander instead of the Focus. I would probably find the nicest AWD available for approximately $9k. It would probably have triple the mileage of the focus and be way less nice than the Focus but be more reliable, depreciate less and be a better tow vehicle. Otherwise I could replace the Corolla but then I have a higher cash outlay and I still have the depreciating and less reliable Focus. I only drive about 8k miles a year so the gas hit wouldn't be too bad and I would probably make up the transaction costs/gas pretty quick with better depreciation and less repairs.
TL DR - I'm thinking of selling the Focus in exchange for a V6 AWD Highlander. In a few years I would likely replace the Corolla with a Prius. I think the ideal situation 3 years down the line would be I'm driving the Prius, my wife is driving the Highlander for our future kids and we have an F350 for the upcoming boat purchase. The bad part of that plan is my wife gets shafted because she never gets to drive the "new" car (since she drives more miles than I do).