Driver display detecting other cars

[MarkSponge]

Sorry if this is a silly question but I've searched and can't find an answer.

What do I need to do to enable the grey cars/bikes showing on the left of the drivers display?

I've tried a number of combinations of ACC, TJA and LKA but it never shows anything. I thought it might be because I have an SR but I've seen it in photos of other SRs. An example of the "grey cars" below.

It's going in to the dealer on Wednesday for the oil leak so need to know if I should add this to the list.

 

[dsimpkins]

I've also seen it display lorries on the display. Now I'm tempted to drive to the station and the airport to see if it can detect planes and trains!