The SP units are part of the 2006 Columbus summer crime task force. They are NOT dispatched units, but float around the hotspots as extra support. The initial purpose was to round up as many wanted persons as possible, and now the focus has shifted towards street-level criminal activity. They are not plain-clothes - each zone is still running their own P/C units.
Most of the SP units are in the Franklinton/Hilltop areas, the near East side and the OSU (off) campus/Wyland Park/Short North areas.
I forget the exact number but there are around 30 cars available, but generally 12 to 15 SP cars run on B and C company. Most of the SP cars are "R" cruisers remarked as SP-xx. These are overtime slots, which is why the number of cruisers varies - no officers are 'assigned' to SP.