I have come across two types of these lind chargers / inverters. One type seems OK, the other causes noise due to voltage drops along the power cables.
Try running the laptop on battery and connect both leads from channel A to vehicle ground. 1V, DC couple, 100ms/div. Now plug in the lind unit and see if there is any change in noise levels or voltage.
Whilst not much help to you as you already have a 12/16V inverter, I find its cheaper and less problematic to buy a mains inverter (cheap as they are consumer items) and then use the normal mains power supply for the laptop. Avoid the really cheap ebay ones though as they are also noisy.