I have transported a Pygmy double on my Honda Fit with just foam blocks on the Thule square crossbars. Bow and stern lines attached of course. I had no issues.

Dan

 Way back when, 2011, we had to switch to an assisted loading rack. In the process, discovered that not all vehicles could take the torque or stress exerted. I would check out the different racks and their lists of "acceptable" vehicles before venturing too far. At the time, the Subaru models didn't meet the requirements for Thule's Hullavator. Times, and specs have changed- time for more homework.  

Sorry for the delayed reply.

We have had a Shearwater Double for nine years.  We love the boat but as a S&G it is a bit on the heavy side.  Our default method of transport is a trailer because it is easier to load and we often take a small fleet for weekend trips. Here in Florida the trailer is actually easier parking because many of the launch ramps have "trailer only" parking.  Many of the dedicated kayak trailers fold up so that they can be stored in small spaces.  The tongue on our Malone is removeable so the trailer will lean upright against the wall in our garage.

For trips where the trailer is not desirable, we have transported the SWD on the racks of our old 4x4 pick ip truck.  The picture shows the boat on foam blocks but we later replaced the blocks with a set of Hully Rollers on the back rack and cradles on the front.  Although I do not like doing it, I could actually load the boat by meyself with this set-up.  I use a step stool to lift the bow onto the rollers, then pick up the stern and push the boat forward.  Obviously this approach is easier with a second set of hands. This picture was the very first time that I loaded the boat on the truck and it is too far forward.  After this, I centered the boat on the two racks.  

I have no direct knowledge regarding the vehicles that you mention, but I suspect that the SWD will be easier to load than a large truck due to lower rack height.  I mention the Hully Rollers but there are many other systems which are designed for load from behind that will also work.

The one concern that I do have is the spacing between bars of the small SUVs.  Many of us with LONG boats use some sort of V-racks mounted on a long bar to support the boat.  You may be able to find such a system that is wide enough, but am not certain.  Many conside 3' minimum bar spacing for a transporting a long boat.  This picture is the Mysteru loaded on an 8' V bar on my new tooy hauler.  Racks on the new truck are 4.5' apart.

Thanks for the (very useful) replies!