It depends -

Family car/truck - not a lot since so much now needs a special tool - jumpers, pair of pliers, small crescent, couple of screwdrivers, flat fix in a can. My truck does get one special tool though - a nice l-o-o-n-n-g breaker bar and impact socket to remove and reinstall those 8 lugs per wheel at 150 foot pounds

Rod - it gets a minor tool kit, possibly only enough to do a 9" diff change out, valve job or bearings