Stupid question, but was the parking brake just every so slightly on?
Also, have the dealer read the OBDII code (or buy a code reader) and see what the ECU thinks the issue is.
By the way, the other "mystery beep" that I finally figured out was that the Maser will beep whenever the temperature goes above or below 35 degrees Fahrenheit, as an ice warning (or non-ice, go ahead and floor it notification?).
Also, have the dealer read the OBDII code (or buy a code reader) and see what the ECU thinks the issue is.
By the way, the other "mystery beep" that I finally figured out was that the Maser will beep whenever the temperature goes above or below 35 degrees Fahrenheit, as an ice warning (or non-ice, go ahead and floor it notification?).