In response to some requests by PM from zx16v, and another PM from yassirau, I am posting another version of the gear indicator. It is far from being a minimum-hardware design, so don't rag on me about the large number of diodes!
It avoids the need to learn to program a PIC, and, for those who may not have easy access to components, uses a minimum of different component types.
This design uses a common-cathode display, and has indications for 0 (reverse?) through 5, and uses "-" to indicate neutral. The "0" can be changed to some other symbol by changing the connections of a few diodes.