Probably "too much information" here on the actual topic, but Just our experience in 2014. :lecturef_smilie:
After NOT Knowing of the 3 wheel endorsement requirement in WA, until a NAPA person asked me where to take the test for the endorsement, and me saying you don't need one
per my dealer who looked at my current MC license, I found out I was wrong (not the first time, but you know :dontknow:.......) I had to scramble and find a class in 1 week, because we wanted to leave on a 2 week trip as soon as possible (I already had 700 miles on the new Spyder):roflblack:.:yikes:
Found 2 day class 50 miles away,

and did this over the weekend (traveling back and forth in car), before leaving on our first 2 week trip ever in late 2014.
WA state requires a 2 wheel motorcycle license to start with (which I had for years), and then this additional special 3 wheel training class. :dontknow:
For most that means spending 2 days "somewhere" for the special training session for the 3 wheeler. Class fee was around $300 as I recall. Getting to and from location is on you.
Class was not specific to Spyder, and actually one of the "how to" training activities couldn't be done with a Spyder (as I demonstrated for them, and they "waved the requirement").
As I remember it had to do with start out in first gear and at 20 MPH shift to 2nd gear and accelerate to 40 MPH and stop quickly from there. Computer won't allow shifting up at that slow speed :banghead:
Nuff said. Got the endorsement and took our first "REAL FUN" trip :yes::yes::roflblack::roflblack: