I wouldnt have thought you'll get much cheaper than 3k a year at only 20 years old. It is a group 19 car after all (20 if its an sti). His insurance will drop quite rapidly over the next few years, mine did. I was 23 when I got my scoob with 3 years no - claims I was still paying nearly 1.5k. Am now paying under a grand a year and am 25 in Jan.
Remeber other factors can also come into the equation though such as location, where its parked etc etc. It all mounts up.
Tesco used to be good for young driver quotes, have you tried them?
Iain