18" alloys

will 18"alloys with an offset of 42 fit a 20vt.
ste.

Ste,
There is no way of telling if they will fit unless you offer them up to the coupe's front wheel.
The Brembo calipers are a real nightmare when it comes to fitting wheels no matter what offset you go for, the only way to be sure is by trying them.

There are other things to consider when changing wheels. you really need more info about the wheels...

For a 20vt, you need (iirc);

PCD 4 x 98
Offset 30-35
centre bore 58.1

The PCD really needs to be 4x98, although if the PCD is 4x100 you could use 'correction bolts' to achieve fitment.

A wheel with an offest of 42 would need spacers of at least 12mm achieve (brembo) clearance.
(centre offest 42mm + 12mm spacer = offset 30mm, spacers are used to reduce the fitment offset from the centre line, make sense?)
personally I would only ever use hubcentric spacers.
*correct length (ie Longer) bolts must be used in conjunction with any spacers*

Also the centre bore must be correct for the wheel to sit correctly, if the centre bore is too big you will spigot rings to correct it. If its too small dont bother.

Hope that helps
(changing the wheels on your car yourself is your responsibility, please ensure you consult/employ a specialist if there is any doubt this will not be done correctly)

Ninja