It has been common practice for many years, for police vehicles in N.I. to have modifications which may not be found elsewhere. The most obvious example is probably the Land Rovers which used to be used for regular patrols.These were armour plated (for obvious reasons) and were so heavy that they had turbos fitted to try to compensate for all the extra weight.It is feasible that some Omegas had engine upgrades of some description for similar reasons.Soeone mentioned in another thread that Peter Robinson was seen arriving at stormont in an Omega.I would bet good money that the car had been armour plated.had bullet proof glass etc, so god knows what it would tip the scales at,over 2 tonnes I would imagine.It would also be a safe bet that it would be required to have plenty of grunt in order to make a quick getaway if an emergency situation arose, so it would come as no surprise to find it had been chipped/turbo,d or whatever.