I need some advice, i dont know what to do and I'm afraid.?

my parents are divorced and i live with my dad and my mom lives in another town 100 miles away. I'm suppose to go see my mom today at her house. the problem is that my dads car is in bad shape. the strut is starting to wear out. my dad doesnt have any money to get it fixed. we talked to an autocar expert and he said it would not be safe driving 100 miles on a bad strut. the car guy said that if my dad drove out there and if he ran into a chuckhole, it would make the strut break and have us get in an accident. i dont want to go that far to visit my mom and have something happen. my grandma told him it wasnt a good idea. i agree with my grandma and i tried telling my dad that its not safe and he is still going to drive me out there. the problem is that if i dont go out there my mom would be mad at me. and then me and my dad would be risking our life over a stupid car. im scared. i dont want to risk it. i told my dad 5 times that its not safe and he is still not listening. what should i do?