Mine have the spikes too, but they certainly dont stop them from moving around. I'm forever trying to reposition the mats and line up the screwtops with the holes in the mats again. :censored:
 
Mine were free too. :)

All the mats with the spikes don't really move around which is fine, but the front passenger one without the spikes always ends up half way up the back of dash board - just don't undertand why it's not got spikes!

(Just to confirm, when I say spike I don't mean the screw things you attach to the carpet, but the hundreds of moulded spikes on the underside of the mats themselfves)
 
I got mine free with the car and mine is the same, just the passenger mat.

Any way of keeping it stuck to the carpet?