Extra bolt holes on the back underside of the radrover 6+

[Kennethdr1]

What are the additional bolt holes for on the red rover 6+ I noticed them just by the rear wheel underneath on both sides of the wheel

[rsghowellnj]

I have the same on my RadExpand 5.  I believe it is for ABUS Wheel Lock but after chatting with ABUS, they don't make an ABUS Wheel Lock compatible with the RadExpand 5.  Looking at RAD Power Bikes the ABUS Wheel Lock that they sell is not compatible with the RADRover either. https://radpowerbikes.pxf.io/1r0R4D

[Porthole]

For quick and easy always available the Abus rear wheel lock would be nice to have on the 6+ series.

[cal]

I actually sent pics to Rad asking the same question. Never got an answer. Probably due to staffing cuts.