[Tools]

There is no "model year" for releases and most letter prefixes are used from as little as 2 years and some much longer (A and P 1997-2000). They have almost always had at least two letters released at once and sometimes as many as 4 (1997-2003, U, A, P and K)

The current releases are Z and M.

The letters left are B, G, H, I, J, Q, and V..... I'll bet it is one of those next..