I got this information from a reliable source, so I am publishing it here for my reference of course and to others if they are interested to know.
1. Tanjong Katong Flyover.
2. Telok Blangah Viaduct. Flyover over Telok Blangah road along World Trade Centre.(near Carribean Condo)
3. Upper Changi Road, at a secluded lobang opp Singapore Expo.
4. Hougang Ave 3 towards Ang Mo Kio. (below the flyover)
5. Upper Serangoon Road, opposite Serangoon Sec Sch, towards Sengkang.
6. TPE just after Tampines Ave 10 exit. (under the bridge)
7. Jalan Boon Lay towards AYE. (Near Chartered Industries of Singapore, Jurong Point)
8. Lentor Ave.
9. Clementi Ave 6.
10. Upper Thomson road, near Island Country Club-overhead bridge, speed limit 50kph (Peirce Sec Sch)
11. Bartley Road / Braddell road (opp old Outram Institute) before underpass.
12. Pasir Panjang Road. (between the wholesale market & PSA Gate 5)
13. Gambas Ave towards Woodlands.
14. Mandai Road.
15. Tampines Road adjacent to Paya Lebar airbase.
16. SLE joining CTE. (under the bridge)
17. TPE Sengkang exit. (under the bridge)
18. KJE. (Along road shoulder, near new military camp)
19. KJE Choa Chu Kang exit. (under the bridge)
20. SLE towards Woodlands Ave 2. (under the bridge or after bends)
BMW / Volvo Sightings:
1. East Coast F1 car park. (aka Last carpark)
2. TPE leading to Sengkang / Punggol.
3. AMK Ave 5 leading to Sengkang.
4. AYE. (Jln Ahmad Ibrahim near to Jurong Bird Park)
5. SLE near Yoa Chu Kang.
Spot Checks / Roadblocks:
1. Fort Road exit.
2. Loyang Road.
3. Yishun Dam.
4. Robertson Quay towards Havelock Road. (Near Liquid Room)
5. TPE (SLE direction) Hougang exit, at the Huge bend. (Saturday nights usually)
Speed Camera sighted:
1. Bedok Reservoir Exit from PIE.
2. Bedok Reservoir Road. (near SAFRA)
3. Before CTE from MS.
4. PIE exit to Science Centre.
5. Lorine Road exit towards Bishan.
6. St. Nicholas Sec School outside the gate. (the downslope leading all the way to Bishan park)
7. ECP Marine Parade Exit.
8. Bkt Panjang Ring Road. (almost once a week)
Moral of the story: Drive safely or say cheese when you see a flash while driving 🙂