It all depends on how deep you want to dive into repair at a roadside I for one carry a HF 1.5t jack Snappy 36" breaker bar and a 3/4HF Bar with lug sockets a full size spare it's a jeep some fluids hose clamps fuses a screwdriver two pairs of vice grips An extra belt ratchet and a few sockets and wrenches
But I'm not doing a you joint on the side of the road it's a four-wheel-drive it will make it home
also have a large EMT kit and large Fire extinguisher flares and reflective triangles jumper cables tow rope ratchet straps duct tape electrical tape sometimes a jump pack we have even take My top box depending on what the plan is trip wise Always have moving blanket work pants a shirt and usually a jacket window cleaner and wax plenty of rags I keep the back of the Jeep pretty well-stocked but it's like my mobile work truck