When I bought my current ride, State Farm let me put comp only on it (you don't get a pink slip), for a trivial amount. Definitely protect it against theft/fire.
Insurance (at least with SF) is pro-rated. SF uses 6 month terms, and just uses an "averaging" type billing. i.e. you pay more in the winter than the actual insurance cost, to offset the higher summer costs, that way over a year, you pay a single monthly amount. If you wait till may to add liability (to get your pink slip), your going to get a hefty bill for the first 6 months, roughly 85% of your yearly cost. Hence the pro-rating. I would just put it on comp only for now, even though the liability cost is low in the winter, no sense paying for a small amount liability when you don't have to.
There is no benefit to giving them more money now than you have to. Use the capital between now and may to increase your on hand cash, should you require it temporarily between now and then
