A good underpad is vital to good carpet wear. If you don't have underpad, you could put small sections of old carpet under the new carpet where the front seat feet sit.

Thanks all-  good ideas all.  
Kim

...or, you could also use a couple of sections from the old carpet as extra cushion.

These can be found here: //www.minispares.com

You could just make some heavy plastic strips (I'm thinking cut them out of a black engine oil bottle) and stick them in place on the carpet with the hook side of some self adhesive velcro. Once they've had some pressure on them, they won't move around.

Why not take four thin pieces of metal strips maybe stainless and pop rivet them in place. Use a plastic washer on the back side of the carpet.

850 Mk1  Looking for a cheap easy hack to glue something on the seat wear points on the rear carpet.  Car came with the cheap black new carpet set instead of the expensive Newton version. Expensive version seems to have plastic/rubber wear strips embedded in back where the front seat frames rest.  Just cut up a black rubber floor mat to 4 popsicle sticks sized pieces and glue?  
Thanks for any thoughts- clearly not  a big issue but bigger issues await clearing the xmas $ budget overhang.....
Be Safe.
Kim