Poppa - I used the McMaster Carr Super High Adhesive velcro on my driver mats as well - it works like a charm, this stuff from McMaster sticks like crazy, I've removed the mat about six times for cleaning and this stuff is STRONG!
I think the 3M tape may be too much for the mats...you will NEVER be able to get them out if you ever want them out.
Got the plate at europlates.com, they have just about any style or color you'd like.