sir/madam,
we four friends are planing to buy a car through car loan on friend 1 name.
but all four friends need to make a aggregement for payment of loan and maintenance cost.
for these aggregement which stamp paper must be used and that aggregement should be registered or notrified.
You can make mutual agreement on stamp worth Rs.100/- and shall be notarized. But the deed shall be got drafted by an Advocate/lawyer.