High-touch surfaces see a lot of hands and are most likely to be covered in germs and bacteria. While the entire outside of your ride might be filthy after off-roading, you don't have to disinfect the entire vehicle, just those high-touch areas. Usually this is stuff like ATMs, gas nozzles, and door handles, but on your vehicle, think of the exterior door handles and trunk pull.
When it comes to disinfecting surfaces, some people immediately think of isopropyl (rubbing) alcohol. Alcohol is great at cleaning a wound, but terrible for cleaning paint. If your exterior door handles are painted, skip the alcohol. Hand sanitizers are generally around 70% alcohol, which makes them too strong for painted surfaces. On the other hand, if you have unpainted plastic or metal door handles, those can stand up to alcohol's cleaning power. Just wipe onto the surface with a microfiber cloth and let dry. This is obviously a less than ideal solution, so here's a better idea.
Your average car wash soap is designed for this job. In fact, a newsletter published by Harvard Medical School stated that soap and water are more effective than alcohol-based sanitizers at cleaning visibly dirty surfaces. A pressure washer with a foam cannon attachment is overkill, unless you're going for an overall clean. You don't have to go all-out with car show prep, but follow an average detailing regimen if you're worried about exterior cleanliness..