Yes use a hiar dryer to heat them up to help getting them off then continue to use the hiar dryer to remover the remainding glue with ya finger.
You can get Z mats of ebay cheap enough
http://cgi.ebay.co.uk/Nissan-350z-Floor ... 0044942788
also Holdcroft do them which is a Nissan Dealership and you can get a forum discount to. See OEM parts in forum discount section.