I will tell you now you will not be able to fit a new hood yourself without any coachtrimmer experience, they are supposed to be b1tches to do and if you reckon you can cut out the hole for the back window and do it right first time, then go for it.

Expensive mistake if you get it wrong.

If she takes something stupid like £500 for the cab then buy it, if you pay 1k for it then it'll cost you between 4 - 700 to get a new hood bought and fitted properly so that's 14 - 1700 in it before you start doing anything else, but at the end of the day it's your money and your choice.

P.S. Cab's are for big girly hairdressers anyway.
