Gliptone is the nuts BUT have patience and follow the instructions religiously!
What it won't do is make seriously cracked and abused seats look like new, so don't go thinking it's the be-all and end all of leather repairs.
It will not fill wide cracks, it will not magically put new leather onto the canvas, but it will make the repair look much, much better then it did.
I've used it once on an old Jag with red leather, and it's stunning stuff - I mean, the difference between the before and after is amazing.
