Yes they are fantastic, but very large, and my wife would never be able to see inside of it.
I have used them before and been very happy with them
The main issues with the Grenadier is not much floor area in the back but plenty of height and nice square opening
The Engel 35 (32L) is 750 deep x 370 wide x 400 high
The Dometic 140 (135L) is 619 deep x 525 Wide x 815 high
The rear of the Grenadier is only 800mm deep so an Engel type would only just fit whereas the Dometic would fit comfortably
The width between the wheel arches is 1,064 so even though the Dometic is 150mm wider it is still only taking up half (49.3%) of the width.
The Engel is 21kg compared to 30.6 almost 70% of the weight for less than 24% of the capacity.
The cold air falling out is correct but as access is easier you have the door open for less time. Particularly if you take something out and everything else fills the hole in the Engel.
The real problem you have nailed is that things fall over easily and extra care needs to be taken but there are accessories for this.
The same can happen in the Engel if it is only half full.
It draws 7.7A max which is a concern but I have gone for the auxiliary battery and Ineos have conveniently supplied a roof switch allowing the auxiliary outlets to be left on when the engine is running.
I could always go for smaller versions of the Dometic but I would rather have more space than I need rather than need more space than I have.
As there is only my wife and myself typically there is plenty of other storage space in the back and with the back seats folded
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