The Main Reason are: 

(a) Criminal element's abode out side ICT. 
(b) Too many entry/exit points to Islamabad, for car lifters it is only 15 minutes drive after commiting crime.
Efforts to prevent this crime:

Anti-car lifting squad has been created after splitting the CIA Islamabad. i.e., 

a) Anti dacoity /robbery squad.
b) Anti car theft squad. 

The anti-car lifting squad  is headed by a DSP. CIA is trying hard to develop their own information network outside the ICT, which is likely to bear fruits.