So far we've raced the Senna and 720s from 0-100mph and back to 0 again, and sent them both on flying laps of Anglesey circuit to find out which is faster around a track. You won't find any spoilers here, so will have to go back and watch parts one and two if you want to know the results.
Today's penultimate episode is only interested in one thing: which car sounds the best? We compare cold starts, stationary revs, launch control acceleration and full-on track attack engine roar - but which car comes out on top is up to you.
Vote in our poll at the end of the video and we'll announce the winner in the final part of the series, which will land later this week.