took it for its 4 wheel aliment which wasn't a bad price £44, £58 including vat
4 wheel alignment is generally a waste of money on the Omega, it needs a full geometry check. Ultimately, 4 wheel alignment offers little over simple tracking. The Omega suffers 2 major geometry issues that 4 wheel alignment will not pick up - rear tracking and front camber.
Full geometry checks can be quite expensive, but fortunately we have a club agreement with Wheels in Motion in Chesham (only), where a full geometry check is £60+VAT (as long as the castor doesn't need adjusting - I believe this is a little extra, but rarely needs adjustment). Wheels In Motion also use a slightly tweaked set of geometry values, rather than the manufacturer settings which are flawed on older cars.
Given your location, near to Chesham, its worth the extra £14 over what you paid to get it done properly. You'll easily save the extra on tyre longevity

You need to book at Wheels In Motion, and mention Omegaowners for the discount. Alternatively, PM wheelsinmotion here, or via their forum -
http://www.wheels-inmotion.co.uk/forum/index.php