It's the same sort of work-around that Subaru used when they brought over the BRAT. They cleverly bolted rear-facing jump seats into the bed when they imported them. This allowed what was a little pickup truck to be classified as a 'passenger vehicle' for tax purposes. Adding $50-$100 worth of seats saved Subaru thousands of dollars in taxes on each BRAT they sent here.
The seats were often removed by the Subaru dealership as soon as the BRATs arrived. When I was in junior high I remember my buddy's dad had a Nissan 720 4x4 with those Subie jump seats bolted into the bed.
There are LOTS of weird ways to work around that tax.