The lower outer partial skin might be a good opportunity to use some panel bond to eliminate the bulk of the welding. Might be one instance where I'd consider a lap type joint.
Lap joints will have two layers of metal on one side of the joint and one on the other. The problem you will have is that two layers of metal is slower to heat up and expand, and slower to cool down and contract when the vehicle is exposed to heat from sitting in the sun. Given enough heating and cooling cycles (about a year or two normally does the trick) and the differing expansion rates of one layer of metal vs. two will show a ghost line exactly where the seam is located. For evidence of this effect, look at the reflection in this green tailgate
in this YouTube video, it shows a line towards the bottom exactly where the seam is located.
