I have a 59 plate fiesta style, recently had a service (approx 1 month ago) and recently noticed that when stationary at traffic lights for example, now and again theres is a vibration that seems to come from the pedal area, not a heavy vibration but noticeable.Suppose one way to describe it is like it may cut out but not as severe, doesnt happen all the time but want to make sure it doesnt turn into anything more.

Any help would be great