how to fix a wagon 3rd door ??

[roach_juts]

i don't know how you call it , but its the trunk door or 3rd door...
any ways my trunk door keeps on closing, it even got me ( hit on the head)
i cant see no hydraulic shock or hinges with spring so i can replace it

the car is a 1990 wagon 300te

does any body had this bad experience?
any advice to fix it ?

thanks