I suspect many hitchhikers are having a harder time since covid. You know.. that whole social distancing thing. I think a lot of people do their best to distance from people unless absolutely necessary and they probably feel like putting a random stranger in their car isn't exactly necessary. I'd probably make a sign that says "tested negative for covid, still positively need a ride" or something along those lines. Maybe make yourself a cardboard hazmat suit. People get a chuckle out of stupid props. Laughs get rides. Just be creative.