Paperwork, paperwork. ..
A junk slip should be enough to show that the component parts are not stolen which is the primary reason for an inspection.
It depends to some degree on the LEO doing the inspection. .. If they're a "car nut" it's a lot easier.
In California an SB100 registration is the easiest way to get around a lot of otherwise difficult requirements like smog, energy absorbing bumpers, etc.
A Locost is, after all, a replica of a 1959 automobile
Only so many SB100 titles are issued a year, beginning the first business day in January and going until the quota for the year is used up.
I don't recall if its 500 or 750 units this year, they keep saying its going to change.
In the past the quota was usually met by mid February but with the economy as it is right now??
If you honestly expect to have the vehicle completed before the end of the year (ummmmmmm, that's a LOT of work) you could start the paperwork, otherwise I'd recommend waiting until your beast was fairly close to completion.
Life has a way of jumping in with surprises as I'm sure you're well aware. ..
Other than that, save
EVERY receipt!! A 3 ring binder with pocket pages is a good idea, it helps keep everything in one place so you can find it later and after you get done will also provide a nice trip down memory lane every time you show off your shiny new toy.