Vinyl Seat Repair

I just noticed a crack in the Black Vinly seats in my 99 Audi A4. Does anyone know a good way to go about repairing something like that? It's proboly 8-10 inches long, on the left side of the seat bottom, kind of on the bolster part. Also, I've got a small rough spot on my steering wheel (it's leather/vinly wrapped), any ideas on how to smooth that out easily?

Much appreciated,
Brad