as you say your car is on rent till 2011, n car was xli-2009, now in how much you bought that car, n how much you get back approximately, n now days how much you paying to your driver,,,, n how much driven your car,,,,,,, n what mean 10 liter petrol per month thy giving total 10 liter petrol per month or or giving 10 liter extra petrol as bones per month.