I bought some for my 300zx, they come with full instructions to fit them and it takes a couple of hours to get your old covers off and to fit these, its a bit fiddly but not beyond the average persons means.
here's pics of my Z interior....
I had just finished fitting it when i took these pics, the leather settles down and loosens up after a few days. so a lot of the wrinkles disappear..
i had the Z for a further 12 months after these photos before i sold it and the seats stayed looking brand new.
cheers
Andy
EDIT :
just noticed this is NOT the guy i got mine from, mine were REAL leather and from a guy in scotland - SORRY, i'll find out his details.
BUT THE KITS ARE EXACTLY THE SAME BY THE LOOKS OF THINGS EXCEPT THAT HIS ARE LEATHERETTE AND A MUCH BETTER PRICE, I PAYED £700.00 FOR MINE INCLUDING THE EXTRA LEATHER I NEEDED, LEATHERETTE IS VERY CLOSE TO LEATHER AND THE PRICE HE'S SELLING THEM AT IS A VERY GOOD PRICE COMPARED TO WHAT I PAYED..