I would suggest targeting a complete "vertical slice", so you can get something working and see if you are in the ballpark. Limit the frills (i.e. tire heatup and leak down).
At some point you have to "reverse engineer" the cars CPU as well, to know what conditions it will go into enrichment, but you might just call it stoichiometric for now, and assume standard day conditions.
But yah, every time I see a PC steering wheel and pedals at a garage sale I want to build a FE driving simulator around them
