It’s very easy to tap the (amplified) ABS wheel speeds in the cable harness that runs next to the shifter

unscrew the tunnel by the gear stick,
lift the plastic as far as you can,
open out the shroud surrounding the cables there,
find the light green wires described & pictured elsewhere.
You need only hook up to one – I chose the light green / pink.
use a soldering iron to melt the insulation a bit and attach a wire to it
take this wire to the stereo (tricky this bit – my route was convoluted – under the floor carpet, along the side carpet, up the footwellin behind the dash on the drivers side, behind the dash (took the instrument pod off) to the radio)
hook it up to the speed sense pin – was labelled in my Blaupunkt manual.

In the wiring harness there are green and light green wires. The difference is fairly subtle in color. Make sure you get the right one! The four wires from the ECU to the ABS computer are light green with red (marked LGR in the wiring diagram), light green with yellow (LGY), light green with pink (LGK) and light green with gray (LGS). I also found a solid light green wire, no idea what that one is for. Don’t use it