I’m the least favourite sibling, am I overreacting?

When my sister turned 18 my dad bought her a $5000 car. When I turned 21 I got $1000 which I was very grateful for. My brother has just turned 21 and he bought him a $15000 car. It really annoys me because I’ve worked hard my whole life where my siblings just live the party lifestyle and blow all their savings. Am I being petty by being annoyed at something like this? I feel so angry at my dad right now and hurt that he doesn’t see me the same as them