1) how rare are these cars? not very - more scarce than 105spec 3i's but still not hard to find
2) are they collectable at all? depends on conidition and milage
3) does thir value keep at a good price or increase with age? prices are rock bottom, i don't think they will ever be classic though

5) Shud i modify the body & to which extent? - does it de-value the car by ££ or by its likeability factor? upto you - will make it harder to sell and you won't get your cash back
6) How far can we mod the engine? whats the highest BHP possible? - any detalis on what to do?
160bhp on stadard inlet and managment - beyond that its a zetec can get serious power... its all about how much money you want to spend