I chose the Calidrawer Ocean 800 for the convenience of using 600x400 and 400x300 boxes. I now have a few of these and grab different boxes from my garage depending upon the nature of the trip, e.g., MTB boxes, or kayaking boxes! They're ideal for a supermarket trolley as well, no need for carrier bags, and it's easy to carry the weekly shop into our home. This has been an amazingly versatile system.
View attachment 31185
You're right that the rear seat has to come forward a few centimetres but it's not been an issue at all. There's just enough space to get the table out, and I've never had a problem getting individual items from the cupboard, although you would not get away with full-width storage containers in the cupboard. I use the left-hand cupboard for pots, pans, kettle, and entertainment items (laptop, chess, etc.) I use only the big drawer for food, divided up using Ikea's fabric trays so nothing moves around. The only thing I wouldn't buy again is light grey carpet, as it has never looked this clean again