adding a trike to the mix

If you are not "motorcycle people" for whatever that means then I would suggest that you steer away from a scooter and look at something on the lines of a "Stallion" by Motortrike. They are in the same price range as all the rest of the trikes yet they drive like a car.

http://www.motortrike.com/trikeThoroughbredStallion.aspx

My wife and I are both still working toward retirement and more RV time with our Class C Itasca. We currently both own trikes. She rides a Harley FLHXXX and I ride a Honda Gold Wing Roadsmith trike conversion. I have previously towed a 14 foot enclosed Wells Cargo trailer loaded with riding gear and two 750+ lb Harley dressers from Montana to Nevada with no issues from my Ford V-10 powered Itasca 29 footer. In a couple of years I will be towing my Roadsmith. It weighs around 1250. I may tow it on my Aluma 10 foot flatbed trailer which weighs only 225 lbs or I may opt for a lightweight enclosed trailer. The one I towed before was a friends and it weighed around 3800 empty. If I buy one I am looking at one closer to 2000 lbs. Anyway I will tell you that you'll need a trailer at least 10 foot long and 6 feet wide to tow either the Harley or Gold Wing trikes. It is much more convenient to have a trailer with a built in ramp like my Aluma. And loading is easier if the trailer sits fairly low as trikes don't have a lot of clearance for the ramp angle. Finally, trikes are fun. They are more readily seen by other drivers due to sheer size and the fact that many car drivers are curious about trikes. Also if it is a consideration for you: some states allow a trike only endorsement on your license so having a motorcycle endorsement is NOT required. My wife has no desire to ride two wheels on her own but I taught her to ride her trike in a theater parking lot and some back roads. She took a trike operators test and rode 980 miles on a 3 day weekend only a few days later. After that 15000 miles the first year.

Trike info

Look here on information on trikes of all kinds...

Good luck

We tow an enclosed trailer with our '06 Goldwing trike in it. Highly recommend an enclosed trailer. Out of sight, out of mind. Plus the trike is covered during wet weather whether we are on the road or at the campsite.
Ride safely,
Alex

The Can Am Spyder is an interesting vehicle. Although I haven't had the pleasure of trying one, they look like they'd be easy to handle. Their dealer network may not be as large as other manufacturers, if that's a concern for you.
There are plenty of kits to turn many different motorcycles into a trike. Harley has foregone the aftermarket and now has a trike in their model line-up. Has the option of a side-car rig been mentioned? If you're going to use a trailer, a side-car offers more room for stuff.
Many community colleges offer the Beginners Motorcycle Safty Federation course (BRC). Often, after passing the course, you don't need to take the road portion of a motorcycle test at your DMV. You'll get a break on insurance, too, so taking the course pays for its self. Private instruction is available , as well. Stop by any motorcycle shop and I'm sure they can help.
MSF
My Gal and I have towed motorcycles (in an enclosed trailer), set up base camp and explored on the bikes. Mainly, we ride the bikes because we enjoy riding the bikes. It's not for transportation purposes. We used to motorcycle camp, because we love riding our bikes, but it was getting difficult to sleep on the ground.
If you're thinking about a flat-bed trailer for the trike, about a 5x10 oughta do it, with a little room to spare. I would think a 5x8 would be too small, considering tie-down points, but I guess it really depends on the trike.
Keep us posted.

Now that we have way of carrying ours, we don't leave home without it. Really relaxing way to see the country. Larry

Now I'm torn.

After reading the first group of answers, I was convinced we would stick with our original plan and rent cars when needed.

Now after the second group, I'm still torn.

To answer some comments made:

I never thought about towing without a trailer - didn't even occur to me that you could tow without one.

I live in Murrells Inlet, SC - I probably see more motorcycles, trikes, Goldwings, Harleys and sport bikes in a month than most people see in a year! I also have witnessed motorcycle accidents and read the stats every year following our Spring and Fall Bike Weeks so we are well aware of safety.

Although we see plenty without helmets & leathers - I know of too many injured people to skip those important items.

Keep the comments coming.

I agree with Carb Cleaner. I have a very paranoid attitude when I ride. I have ridden motorcycles since 1961 and have never had an accident, but there have been several close calls from idiot cagers. I have installed a Stebel horn (140 dB) and it has stopped several cagers from sideswiping me.

People in cars don't see other cars or motorcycles. They don't see trikes, either. The best attitude while riding isn't to assume that people don't see you, the best posture is to assume they see you and are actively trying to kill you. I'm sure you already have, but consider the danger element very carefully. Death isn't necessarily the worst that can happen. Your attention level on a bike should be ten-fold what it is in a car. It's not a good time to sight-see, but riding can be a lot of fun in itself.
Having said that, I've ridden thousands of smile-filled miles and only limp on one leg. It's worth it to me, and I continue to ride after limping for 25 years, but not everybody feels that way.

One of the problems with towing a motorcycle is that it is necessary to disconnect the drive wheels(s) when towing so that it can never be in gear during the tow. Some models have a chain which is relatively easy to remove, but some have a drive shaft which is a real bear to disconnect.

You might well consider putting it on a trailer so that you avoid that problem plus not wear down the tires and make them square.