I wear a T-shirt, plus a tallit katan, plus a button-down shirt, and I bike to clients' homes. Let's say I want to change into a (clean) tallit katan before entering a non-Jewish client's home.
Is it reasonable to change it while standing in the client's driveway, before ringing the client's doorbell? Or could this look unprofessional?
If the driveway isn't a reasonable choice, then where else can I change it?