The 'Cruiser was an '07 with 135k miles on it. I decided that this season, at 61 years old, I just wasn't up for crawling under the 'Cruiser regularly to drop the driveshaft any more. I just don't want to do it any more. A REMCO driveshaft disconnect from REMCO in Des Moines is about $1100. The 'Cruiser needed wheels (corroded from road salt) and tires, and I figured it'd probably need a clutch, brakes, and water pump in the next 20k miles... so the question became, do I drop $5-6k in the next couple of years into a nine-year-old car worth $10k wholesale... or trade it off and get something newer?
I have some unique needs for it; it has to tow a landscape trailer with my 26hp Kubota tractor in really nasty winter weather conditions for snow removal (and mowing in the summer,) and it has to launch and recover my 21' Precision sailboat at the lake too, so I needed something that I could both tow behind the moho without mods, that can tow 3500 lbs itself, AND has 4WD. After doing significant research, it appears that Jeep and Chevy Colorado are the last vehicles that can do that. And I'm a Jeep kind of guy.
That sent me to Jeep dealers looking for used Jeep Wrangler Unlimited 4drs. I was appalled at their resale. Used '14s and '15s with 30k miles were $35k. The last new car I bought (for me, my wife has had several) was in 1993, and the last new Jeep I bought was in 1981. But for the small difference in new and used prices, I bought a new '16 equipped the way I wanted it for only slightly more... and I bought an unlimited mileage Chrysler warranty for it. But this tale revolves around towing...
I had presumed, and the dealership had confirmed that towing the Jeep on a dolly would be no problem as, after all, you can tow them 4 down. I presumed that wrongly, and the dealership confirmed that in error. AFTER we bought the Jeep, we'd had it a few days and my wife pulled the owners manual out and read it. (Can you believe this... she actually READ the owner's manual. I was deeply ashamed... but by then the deed was done.) Anyway... she found that, according to the owners manual, the Jeep CANNOT be towed on a dolly. Four down, yes. Dolly towing, NO. So off I went to my Jeep dealer in search of answers. I got nothing definitive except that maybe the splash lubrication of the transfer case is provided by the front driveshaft turning (which of course requires the front wheels to be turning to turn the front driveshaft.) The lead service technician added nothing meaningful to the conversation other than to confirm that it cannot be towed on a dolly. He wasn't sure why it can't be dolly-towed either.
So... at least it IS easily towable 4-down just by shifting the transfer case into neutral... *sigh*
Having never towed 4-down before, I had to research what I needed, and then pursue those parts. My octogenarian father has (and continues to) towed 4-down for at least twenty years, so his advice was invaluable. Craigslist is our friend, and I found a Blue Ox Aladdin aluminum 7500 lb tow bar with safety cables and the electric cable for $300 in almost-new condition. I needed a base plate for the Jeep and found a new-return on Amazon Warehouse for half-price at $201 shipped free with Prime. I got the Chrysler 7-pin round factory wiring harness for $86, about $50 off list (again from Amazon,) and the taillight wiring kit from Amazon Warehouse again for about half-price. I sold the EZE-Tow dolly for a little more than I paid for it last Spring (again, Craigslist is our friend) in about a week.
I have a good friend who is an auto-electrician (an electrical engineer by education) and an amazing mechanic who has a shop here in town. It took two days in his shop to get everything wired (including the Prodigy brake controller,) a seven-pin connector installed on the coil-cord, and the baseplate installed. He solders and shrink-tube wraps all connections and joints for electrical reliability rather than using butt connectors. The wiring install looks absolutely factory.
So, for $683 in labor for the baseplate and brake/taillight wiring and tow wiring harness and brake controller install, plus about $620 in parts ($1300 total) the Jeep is now ready to tow and is ready for towing. Fortunately, I'm about $400 to the good after selling the tow dolly, but of course I'm limited now to towing the Jeep. The Prius is "off the hook" so to speak. Had I bought the tow bar new, it's list is $995 (street price of about $800.) The coil cord is about $100, and the baseplate about $400, so by shopping I saved about $1000 in parts costs.
So, that's the titillating tale of my travails in toad towing (and equipping...) Hopefully, with the lifetime warranty, this Jeep will last me until I'm too old to drive... maybe another thirty years?
Well, I expect it to last at least twenty! 
So if any of you have questions about what NOT to do when buying a toad for four-down towing, I'm a veritable walking encyclopedia of what NOT to do!
That's what made the dolly such a good choice was that it allowed me to choose which vehicle I wanted to tow. Now it's JUST the Jeep... but I'm ok with that. It'll be a good car to have on the road with us.