okay omg dys car runs perfectly but too many other problems like leak rust n all im trynna fix its worth it bot for $800 =D 117k miles on it with just a little rust broken sideview mirror

and a leaking hatch well i fixed da broken mirror m fixing the rust this weekend but idk how to fix the leaking hatch i mean whenever it rains theres no water on da hatch glass or nething i think its either comin from somewhere undereneath the car? maybe a hole or something? or could be the tail light seal any suggestions how to fix it?