Why is the weather radar mounted on the left wing of the TBM?
After some detective work I have concluded:

In the TBM planes, the center portion of the right wing leading edge is occupied by the stall warning vane (or an optional AOA sensor in newer models). The two pitot tubes are located under each wing and landing lights are positioned at wingtips. This would leave the current location for the optional weather radar pretty much the only option available.



TBM 700C pilot information manual, stall warning vane description on page 7.15.1

Source for picture