I need to ask my boyfriend to sadies and i need a really cute idea! the theme is 70's and 80's dress up. Help!

last year i did this cute puzzle thing but this year i was thinking a scavenger hunt kinda thing but i honestly dont know or i was also thinking of decorating his car but thats not original but i dont know as you can tell cause i am ask so please help me i would reallly appreciate it :)