Another alternative are Cocomats. Extremely durable and do an excellent job of protecting the carpeting under them. Had a set in our MINIs for over 5 years and the carpeting looked like new.
The look may not be for everyone, but I got lots of compliments. I'll post pics when our 135 arrives (hopefully) in mid-July.
The company website is
http://www.cocomats.com
(No affiliation on my part, just a satisfied customer).