Yeah, I was too brief.... The goofy track solution of yesteryear was a disaster. Bet most are now disabled. The track (only in my mind) was about six inches across the roof ...no motor. Sort of an adjustable four-point minus one. Would be interesting to know if Lear vends a seat with in-seat shoulder belt and price delta compared to the stocko. If the tracks can meet the standard, might be a good choice. Unfortunately, real world crashes show car seat backs are notoriously weak (admittedly in the other direction). (Driver/front pax seat is catapulted into and kills child in back seat when car is rear -ended. Driver walks away uninjured.) Not sure who makes MB seats. Elio has opportunity to give us that option if engineered now.Don't you remember when they had track systems for the shoulder belts in the late 70's early 80's? When you would open the door, the belt would move from slightly behind the driver/passenger across the opening, and down the A-pillar? They got to the point of dangerous. The in the seat option is not that far of a stretch, and can be done by the seat manufacturer for a minimal cost. In my days of working on cars, moving those seats to other cars was not that difficult.