Emir wrote:
DA42 has sensors on front baggage compartments doors as well
Good to know !
I’d imagine one of the challenges in implementing a reliable warning light is that most GA doors are not exactly a good fit 
If it’s not pressurized or inflate for sound proofing, it will wiggle
My PA-28 has a ‘passenger seatbelt not fastened’ warning system. Years ago a renter pilot wrote in the tech log “Loud banging noise in flight”. The quarter panel behind the door still has the dints caused by the seatbelt flailing in the slipstream.
