I think that most folks here got insured after they converted their bus and registered it as an RV. Makes the driver's license required easier too, at least here in CA. I think most states requires a CDL or some other higher level of driver's license if it's still a bus. After converting my bus I could drive it with a regular driver's license and insurance with GMAC is only about $200 a year. Plates are cheaper too. I did a rudimentary conversion on mine over a weekend and got it titled as a motorhome and insured, then started on the 'real' conversion. I was in a hurry, since I had a 20 day temporary tag and wanted to make the trip to the DMV while it was still good and not have to bother with futzin' around getting another temporary tag later - the less to do with the DMV the better
I don't know how hard they look at things there when they inspect them, but out here they just walked through mine and if you don't look at things with an eye towards permanent installations the conversion goes rather quickly - example I hung the black tank in a space where it would fit underneath with strapping iron and set the toilet just above it and fastened down with drywall screws - never connected them for the inspection. Put in the water tank where there was room underneath, set in a vanity and sink from Home Depot (actually plumbed water to that) next to the toilet, half a dozen 1x2's and 3 sheets of masonite and a roll of wallpaper for walls made a bathroom. I put a battery and inverter in the air cleaner compartment and wired one outlet, put in a microwave and a compact refrigerator. Another half dozen 1x2's, a sheet of plywood and a mattress from my other motorhome made a bunk. Passed the audition. Spent a coupla hours the next Saturday morning taking it all out and stacking it in the corner and used all of it in the 'real' conversion. I wasn't out to impress the DMV with the quality of it, I just to get it inspected successfully.
Guess some would say it was a waste of time or work, but I wanted to use my bus before I'd done a complete conversion, rather than let it sit around and fossilize 'til I was done and that weekend is long lost in the early fog of this project.