Wow! I'm 20 too, but i didn't have have a NCD...well i hadn't even held my license for more than a month, so i guess that's why you were able to find cheaper quotes, they see you as way more experienced than me and therefore less of a risk, regardless of same age.
I don't doubt that some people are getting crappy readings, coz it seems like one of those things that can go easily wrong. But to play devil's advocate, my car was £500... The accelarator is so f'd. It's all or nothing. I'm either going slowly... or VROOOOOOOOM. People always think i'm trying to be a boy racer when i move off because it revs so high
Which is no surprise that my Breaking/accelarating is the lowest score out of everything, but it's still 4.2 (out of 5). even after i gave my roommate a little driving lesson and he stalled and revved/harsh braked the f out of my car.
And oh yeah, sorry, yeah it's a Corsa. I looked online, seems to be a really common problem with 93-2000 Corsa Bs... Did yours work properly after you replaced the MAF? What would yours do exactly? Mine drives fine around 30mph, it's when i get on 40/50mph roads and put my foot down - engine light comes on, put my footdown more car slows down/loses power - let go off gas for a couple secs, engine light goes off.