1) what are terms mentioned in your appointment letter?
2)if you are not in agreement with car lease rules and other issues you need not signed the document forwarded to you by your employer .
3) you can negotiate with your employer regarding the contentious clauses in the stamped document forwarded to you .
4)as far as 3 months EMI is concerned request company to take back the car and credit EMI deducted from your salary as you had never agreed for said deduction from your salary