[ScorpiusWireless]

Ok here we have a MPD F1 for Carrera at 24.8x14.2 or 352.16 sq.mm. The F1 chip comes in at 700 square.mm so we have halved it, and still wireless.
The IR LED is surface mounted on the bottom side of the board and fits perfectly. The chip is fixed to chassis using BluTack. 
The braid wires and motor wires were soldered to board or you can leave the wires in that it comes with and solder at non board ends.

As you can see a neat and unobtrusive install.

So deluxe plug n play decoder or mean n lean basic decoder, Scorpius has both bases covered.

Carrera chip 700 sq mm
MPD F1 352sq.mm