I buy cars according to if the police buy them. If the police have them, then I'd buy it.
For example how many Honda Accords, or Toyota Avensis' do you see as police vehicles? There are some...but not widely used by forces.
And again, do they use petrol or diesel?
The Metropolitan Police use 1.7 CDTI Astra's, 3.0 V6 CDTI Vectra's, 530d's and 330d's and a few other. The majority of their fleet is diesel, TVP in the last of their Vectra's had the 3.0 V6 CDTI instead of the 2.8 V6 turbo.
The Volvo V70 T5 is still a favourite amoungst the majority of forces, but from as early as 2006 some forces used the D5 variant. Which is the 2.4 diesel producing 185 bhp.
It may seem odd that I'd only consider something used by the police (I don't neceaasirly mean it must be ex police, only that it's the same model), but think about how much testing and consideration is put to which vehicles are used for the fleet, their practicality, runnning costs, performance, capacity to fufill either IRV or RPU, ARV etc roles, occupancy protection in a crash, cost of repair.
This is why I would never buy a Vectra 3.0 V6 CDTI with an auto box, I have seen far too many come from the Met as non runners with gearbox issues, I've never seen so many of the same vehicle come through as non runners. But the manuals seem fine, so it's not an engine issue...just a gearbox issue. Some came through on about 65k miles, some 100k or more miles so I think it's just pot luck how long the gearbox holds out for.