the guy that had my car before me was messy there are stains and paint a couple of places on my leather,the int is grey and black,i was thinking about dying my seats black,would this look good or bad?

 

I think the black seats would look cool. But thats if they come out good. I don't know how good you are with dying leather. I know i wouldn't trust myself to dye leather seats.

you could try saddle soap to remove the stains or go to a detail place and see if they can clean them.

OR have the seats professionally dyed.

 

i'd try some leather cleaner or saddle soap as well. Black seats would look cool in your car. They would get hot in the summer though but you already have gray seats so dying they wouldn't make that much of a difference. Good luck in what ever you do