Surely I wouldn't need the 4 wheels aligned as it was only the front that got the love??
Correct. 4 wheel alignment is a waste of money. You need a full geometry check done on it.
So whats the difference between 4 wheel alignment and full geometry change check?
4 wheel alignment basically checks that all the wheels are in the same postcode and pointing in vaguely the same direction. This is fine on a wwd shitbox, as the rear wheels only exist to hold the back end up off the ground

A full geometry check is a three dimensional (camber and toe front and rear, front castor, and chassis thrust angle) check of all four wheels, positioning them precisely in relation to each other
and the chassis. This is much more important on rwd and awd cars as the thrust from the drivetrain comes from the back, and some cars, including the Omega, have quite adjustable suspension components, so the geometry is key to both tyre life and the way the car drives
