Top: Male OBD-II connectors and pins.
Middle: STN1110 multiprotocol vehicle interface IC.
Bottom: MCP2551 CAN transceiver IC.
(Note: We also have the female version of the connectors, female terminals, and the appropriate crimpers.)
None of this stuff is particularly expensive or hard to find, but in i3’s electronics lab, it’s already been picked out, ordered, shipped, and sorted. With this potential within arm’s reach, what will you build?