I am looking into the bendefits of salary sacrificing versus a loan but am unsure of which way to go.

I earn $120,000 per year and would like to salary sacrifice and get a VW Golf at around $42,000. However if I salary sacrifice, this reduces my income to about $78,000 and does not get me to the next tax bracket which is the whole aim of purchasing a car with pre-tax dollars. i am also ensure what the repayments would do to my monthly salary. Where can I find information on this or should I get take out a loan?

many thanks