right! so we all invest in expensive trackers....i mean...even the cheapest GSM based tracker is for around 15000 (I think)....and still thee thieves can disable it if they know there is a tracker in the car....
so here is a simple way to make a tracker for your car at home......ist cheap ....and you can track your car easily + also listen to whatever is happening in your car....
1: Get an old nokia phone...less than 1000 for a cheap one...
2: Get ufone sim card....
3: switch the phone on and hide the phone somewhere in your car....(connect it to charger etc. )
4: enable "ufone utrack" service...remember the service thay have where you can send a txt to any ufone number and if the number replies...you can trace its location....so basically...enable that...
5: worst case scenario....if you need to trace it....go to your phoen service provider and give them phone details...they can trace it for you...
if you are in UK .. you can use the website like..
MobileLocate: 30 Day Free Trial - mobile phone tracking, track mobile, mobile tracking, trace mobile, tracking, minor planet, trace mobile, phone trace, mobile phone trace, mobile phone location, locate mobile, mobile phone locator, track mobile phon
to locate your phone/car...but in Pakistan...the map thingy isnt available...
o and now how to listen to whats happening in your car
1: enable auto reply in the hidden car phone
2: configure phone to only reply the call from your own phone...
3: whenever you need to listen...call and listen 
thought should share the good old method of tracking ........ of course its not the solution to posters question....but still!!! ONLY YOU would know where the Phone is hidden..... not unless the thieve uses mobile phoen jammer...your phone/car can be tracked!!
REFERENCE : noorabdullah's post above!