I just joined this forum, and a search about towing a Miata brought me only some very old posts, so I thought I might revive the subject.
I am towing a standard transmission 2003 Miata 4-down. I know Mazda doesn't condone it, and I know others recommend against it. But it is such a wonderful car, especially as a dinghy, so I did some research to see if it would be worth the risk, and I am sharing it with the forum, and will continue to report from time-to-time how things are going.
The supposed problem, as I understand it, is that the transmission on the Miata (and other cars) is lubricated by the spray of transmission fluid that is caused by the turning of the shaft that comes from the engine. When the transmission gears are turned by the rotation of the drive shaft turning from the rear wheels of a towed car on the ground, there is not adequate lubrication and the gears will be damaged. That's what they say, anyway.
My RV is a 2006 Jayco Granite Ridge 3100SS with 9000 miles. It is a Class C built on a Ford E450 with the V-10. It's GVW is about 14,000 and the total allowable weight including the tow vehicle (I forget the abbreviation!) is about 19,000, a 5,000 pound spread. The Miata is only 2300 pounds or so.
First, I looked all over the internet and virtually every post I could find by people actually towing a Miata 4-down said they had no problem. I have yet to hear about anyone who has had a problem towing a Miata 4-down.
I called Roadmaster and spoke to a Customer Service Rep. Her comment was, "I have spoken to dozens of people who asked about a tow bar for a Miata, and no one has ever called back to tell me they had a problem."
Roadmaster does manufacture a base plate for towing a Miata 4-down. My RV dealer installed the towing equipment, without any modification to the car. I was instructed to keep the stick in neutral, the brake off, the key in the ignition in the lock position so the wheels don't lock. The steering wheel is not tied up. We are using a Roadmaster Falcon 2 tow bar, rated at 6000 pounds. To be on the safe side, we have a Brake Buddy in the Miata. It cost over $1300, but the last thing I want is to worry about burning out the RV's brakes coming down a mountain.
To me the Miata is the perfect dinghy. It's just about the smallest and lightest car you can buy so naturally it's an easy car to tow. Since an RV is large enough to haul anything when needed, the 11-inch high Miata trunk is no problem! We plan on spending our time in warm climates and can't wait to drive with the top down on coastal roads and in the Rockies in summer. Of course, it only works because we're only two people and a little dog; if you are traveling with a brood, the Miata is clearly not for you.
So far, we've traveled 850 miles, from Albany, NY to Wilmington, NC. Our average trip is under 200 miles, and we plan to keep our travel under 250 miles in a day. When we arrive at each destination, at the very least we start up the Miata to circulate the lubrication and usually unhook the car and drive it around town. So far, so good.
I've been to three Mazda dealers since purchasing the car last month. Once before I bought it, to check out the car, then twice on our trip for non-mechanical issues (once to make spare keys, once to fix a speaker). I mentioned that I was towing the car 4-down to all three service departments and none seemed particularly perturbed.
Disclaimer: I am only reporting my experience. I don't know a damn thing about the mechanical workings of cars, RVs, internal combustion engines, transmissions, drive shafts, etc. (I am a hell of a chef, though!)
So that's my experience so far. Because of the warnings, I can't help but be a touch concerned and will be for at least the next 2,000 miles. If anyone out there has any experience with this, good or bad, I hope you'll contribute to this discussion.
Happy trails, everyone!