Would this be considered my fault?

Okay you remember that episode of Seinfield with the mutant b.o. smell in the car that wouldn't go away?well i have a similar problem.ok i borrowed my friends car for a week to go back and forth for school.anyway another friend of mine said he needed to borrow the car to take this girl out.i started to say no but since he offered to fill the tank when he was done with the car i said ok.now the next day i get in the car and the worst crap smell ever hit my nostrils like a bat.i mean it smelt like someone just came in and just rubbed the all over the seats after eating curry and mexican food.later that day(after taking 4 buses to get back and forth from school)the friend that loaned me the car came over and said she needed the car back a little earlier.so i gave her the keys and she got in the car and 5 seconds later came out yelling at me saying "what the hell did you do to my car"i told what happened but she was pissed off and told me i better have it fixed in 3 days.so what i want to know is whose is is really at at fault?she loaned me the car so it was my responsibility if anything happened to it but i didn't put the smell in the car so .first would telling her it was my friends fault do anything would my friend be responsible at all or is it all my fault?