As an alternative to losing details of these spotteds in a long discussion thread - list the essentials here for easy reference.
Most recent sighting at top of list, even if the car has been seen before.

Date	Car	Reg	Colour	Location	Its activity
24/8/12	Ford Mondeo Estate	55 plate	Siler	Wanborough (Between Pirbright and A31(Hogs Back))	Lights on, pulling me over
23/6/11	Octavia	FD57 PKN?	Siler	M27-A31	lights on, heading to incident
23/6/11	BMW 1 series		Graphite	Chichester/Goodwood	lights on, heading to lorry fire
21/6/11	BMW 5 series estate	HF11 CKM	WHITE	Dean Park, B'th	lights on, with prey
8/12/09	Skoda Octavia VRS	ND57 PJV	Silver	Wilton Av Southampton	just cruising along but saw his uniform!
3/12/09	BMW New 5 series		WHITE	wessex way	lights on, moving fast
2/12/09	Ford Focus New? RS?		Graphite/grey	Lansdowne	lights on, moving fast
27/09/09	BMW estate	HF09 EKA	dark blue	Dorset Way, Poole	on slip road with prey @ 8pm
22/09/09	BMW X5 facelift	YF09 KLJ	metallic grey	Shoreham	maybe just a pool car?
12/09/09	Audi A5?	GX55 GDY	dark grey	Brighton A27	pulled someone around 1pm
15/09/09	BMW estate	HF09 EKA	dark blue	Ashley Heath r.bout	on the chase @ 1730
11/07/09	Toyota Celica	-	Super Red II	Burgess Road/Hill Lane Roundabout	Blue & Twos on, gunning it.
02/07/09	BMW E60 5 Series	-	Dark Blue	North of Petworth, by the 272	Full set of blues & two's on, had pulled over a gagle of Bikers!
02/07/09	Subaru Legacy	58	Silver	A27/A3M junction	I, er, undertook him as he was doing 65 in outside lane & got flashed!!
27/03/09	Ford Focus ST	-	Silver	Patcham/Brighton	Blues and Twos. Pulled over 2 cars. Mates with the BMW guys below
27/03/09	BMW 330d Saloon	**08***	Mucky brownie/grey (Stratus Grey?)	Patcham/Brighton	Sneakily waiting on the side of the road, occupants started licking their lips and using their radio as I went past in the Cerb, but I wouldnt play the game
18/03/09	BMW 5er touring	HF05 FDZ	White	Wimborne Rd nr the Northbourne Roundabout/Old Vicarage, Bournemouth	Blues and Two's the whole bit!
14/03/09	Audi A3 1.8T	-	Grey	M27 between Junction 5 & 7	Being sly but couldn't fool me!
25/02/09	Ford Focus ST	HJ57 HNJ	Metallic grey	East Howe Lane where it meets Kinson Rd (by the shell station)	Lurking with intent!
24/02/09	Merc C Class Saloon	-	Silver	A27, Shoreham Airport/Lancing Roundabout	Blue's on going through traffic. Heading towards Lancing/Worthing!
12/02/09	Vauxhall Astra H	-	White	Kinson RD B'mouth	Lots of pretty lights and irritating noises
11/02/09	Octavia VRS	58 i think	blue	A34/M3/A3	Gave me the slow down when I past him at 90 in a commercial! Thank you officer, sir, grovel...
11/02/09	Octavia	...	Silver	Southampton	Came through red light at crossroads, almost ran me over before putting on his siren and blue's and two's
11/02/09	Merc C Class? Saloon	-	Silver	A27, Devils Dyke turnoff. Westbound	Pulled over a fiesta with blues on all over place
10/02/09	E60 5 Series BMW	-	Dark Blue	A27	Heading through Worthing west bound at the time. Headlights & rear light clusters with blue's in the light clusters working away...Debadged also.
31/01/09	Big white Volvo	'08	White with luminous bits	M27	Was going nee narr,nee narr
29.1.09	BMW E92 shape 3series		Black	A303, Amesbury, Solstice pk	chasing car infront
27.1.09	Astra		Burgundy	Worthing, Dominion Rd	Driving fast with blue lights on
25.1.09	Octavia	...	Silver	Near Gunwharf Quays, Portsmouth	having an offender held in cuffs over its bonnet
25.3.08	Octavia	...	Black	A3, Petersfield	"did me" for average speed 99.97mph over a stretch of 2 miles

(please add previous spots here in reverse date order)