I was on a run today and saw a Fiat 500 Abarth go by and both the exhaust and turbo were making some great noises. I feel like my Saab 93 turbo noise is fairly loud, which I do kind of enjoy. In comparison, my girlfriend's '02 Passat barely makes any noise at all. My Dad's '04 MX-5 Mazdaspeed makes a bit of a whistle at higher rpms.
Now, I haven't driven any supercars or anything of that caliber but what is the vehicle with the loudest turbo you have driven?