my codriver fits best in my spec miata .... because the seat is bolted directly to the floor.
should be able to do that to any miata if you really wanted to. pull the seat out, bolt an aluminum one to the floor, they actually even make weld-in drop floor kits to get a 3 more inches of height. http://mazdaracers.com/store/product...or-drop-panel/
WAY cheaper/better than a lotus. then again, just about everything is.