So today after taking my car for a sorta long trip (120 miles) I start it up and the transmission is going crazy..on the dash where it shows all the gears it kept on flashing and get this, when I put it in reverse it wouldnt reverse!the d and s worked fine but it wasnt reversing...and after like 15 mins the car went back to normal..i still have the manufacturers warranty on it since its an 04 with about 43k miles...I am taking it to a Audi dealership as soon as I can...does anyone know what can be wrong and also what does the warranty cover exactly(parts..labor)?

Thanks