2 way for u to solve yr problem:
1) pay for yr friend!!! coz u r the guarantor, u can't escape from whatever u have agreed!!
2) go get yr friend to sell the car (ha ha ha, sounds easy)
to find out whether u r blacklisted or not, just apply for any credit card, yr banker will tell u whether u r clean or not. Or otherwise, if u dont mind to spend some money (about RM20 - RM30) to make a blacklisted or bankcruptcy search, if u dont know where to go to make a search, go back to yr usual banker, tell them that u want to make a search, some bank may assist u on this but some not, but still, u can ask them for their contacts.Do remember one thing, if yr bank found out u r blacklisted now, they might take action against u too....so, good luck!