I'm puzzled by your answer.
I got a set of brand new Astra Alloys, the 16" version of the ones shown in the picture and they fitted straight away on to my Omega with no spacers or mods.
They'll "fit" no problem, but how far tucked under the car are they? You should check their offset (ET number stamped on the inside of the wheel). The lower the number (in mm) the further out they sit on the car. Front wheel drive Vx cars tend to have a lower offset wheel of around ET45 is whereas a RWD car, such as an Omega or Carlson will have a wheel of ET 35-38.
They may be fine, they
MAY need this taking into account, I perhaps should have made that clearer in my initial reply.
The wheels I have in the picture above came as ET45; I use spacers anyway, even with the standard 17" Elite wheels which were ET35.
Check here for more details:
http://www.nice-wheels.co.uk/Vauxhall.html