Rather than start an entirely new thread, I thought this might be an appropriate place to ask the question:

For a sedan service transfer from JFK to Essex/Middlesex/Union County, what would be an appropriate gratuity for the transfer? I realize that there are a lot of variables that might influence this, but this would be for a regular sedan (no bells and whistles), normal day time hour transfer. I am just looking for a baseline number. Is it a percentage of the total cost, or is there an accepted amount for a similar length transfer?

I know this is a broad question, but I appreciate any thoughts.

Thanks.