I was at OPs income level when I bought my car first car too. However the differences were, I was single and had about 300K savings. I went for 1M personal loan with 3 years payback period. (32K per month)
What I noticed is, unlike housing loans if you can increase monthly installement and reduce the period it'll be easy in long run. HNB, Comm bank and NTB approached our staff, giving personal loans around 9.5% - 11.5% interest rate these days. These are the good days to get a personal loan and make sure you get at fixed interest rate (it's highly unlikely interest rates for PL go lower than this. Chances are, the rate will increase soon)
And don't get fooled with all the leasing offers. My personal advise is don't go for 5 years loan or leasing on a personal vehicle which you have to cashout from your salary. 5 years is quite a lot to use budget car (asume you will go for small car). Apply PL immediately before interest rates goes up, even if you don't buy the car . Save money for couple of months. Don't forget, if you saved upto 6 months, while keeping your PL money in FD, you have recovered some of the loan interest and 6 months are already paid.