It really depends on the design of the laptop mount that you have purchased and installed. So for example, some models will have a quick release catch at the base. In this instance, it would probably be a better idea to simply remove the laptop mount and pop it into the trunk. Even designs that lack the quick release can usually be folded down into the foot well for easy storage. You also need to bear in mind the safety aspect with your laptop mount. For example it can be very dangerous if a passenger airbag deploys and the laptop mount is in the way. It could also cause an obstruction in the event of a collision. Looking at it from that point of view it really is better if you can remove the laptop mount (or tuck it away into the foot well) for both the comfort and safety of your passenger.