You may choose to search volunteer opportunities by series…
However, it is not very likely that a particular series would recruit marshals to work directly for them following all of their events, both domestically and internationally. There were examples from the past like the CHAMPCAR/CART days when certain flaggers were flown to destinations worldwide: Mexico, Brazil and Australia included specifically to work their events. More recently IndyCar relies on a dedicated crew of rescue servicemen who ride around the track in Holmatro sponsored pickup trucks and perform all duties including stalled car restarts, fires, and first medical response to crashed vehicles. ALMS had a similar arrangement with a crew of first responders but they have since been disbanded and TUSC/IMSA now rely on each track to provide those type of rescue people.
It is worth mentioning that a crew of pit marshals do get to travel to all the TUSC events, however it is unclear in what capacity they work or volunteer. As they advertise to also provide pit notes service.
NASCAR is known to employ spotters since they do not rely on flag marshals on ovals and speedways (whereas for the two circuit events of the year in the Sprint series they do use volunteers) however I have no information on how to land that job.
A good example of marshal recruiting by the series is displayed by the Australian V8 Supercars organization. A volunteer portal was set up specifically to allow marshals to register for various V8’s events around the country. The system was not yet in place during the time V8 Supercars were visiting the Circuit of the Americas and therefore many Aussie marshals missed out on the opportunity to volunteer in the US because it wasn’t clear who would organize the marshals here.
The information listed above is based on my experience and I acknowledge the fact that I may be wrong. But I’m happy to be corrected, so please leave a comment below. As the information changes frequently, some of the information listed may not be accurate in the future. I will do my best to keep this updated.
How to marshal: