Yes, that's it!
By 'vain baggages' I assume you mean 'luggage compartment' (boot/trunk) and by 'chest motor' you mean the 'bonnet' (hood)?!
Where I read about this car it intimated that this was Zagato's first use of the roof humps which of course became his trademark, although whether that is correct or not I'm not sure.
Here's another picture of the car: