The most distinguishing feature of "Merc" is the holes in the body.  Below is a series of photos showing the step by step process that makes "Merc" the ArtCar that it is.
In this first picture we see the left side of the car in a 3/4 view. The holes have been cut out with a plasma torch.
It took over 6 hours to cut
out all the shapes.
The paint has blistered
from the heat of the torch,
and rust has already
started to set in.
The rust will be
addressed later.
In this photo, we see a close up of the right front. The holes are badly rusted. The blistered paint can be clearly seen in this photo. The area surrounding the holes will have to be sanded and prepped for paint.
This is the second step of repair to the right front fender area.
The blistered paint has been scraped. The next step will be to sand the area smooth,
to blend in the repaired
area with the rest of
the car, so the repair
doesn't show after
re-painting.
This photo shows a portion of the right front sanded out.  This area has been sanded with #80 grit, followed by #100 grit, then #240. Once it is all smoothed out, the repair area will be ready for "Ospho" then primer and paint. 

Ospho is a chemical that
turns iron oxide "rust" ,
into iron phosphate an inert. 
Any area that contains rust
will turn black. After the area
has dried for a day. It will
accept paint.
This photo shows the left rear, all feathered out.
This area is ready for Opsho, primer and paint.
How the Holes Shaped up
Here is a photo of the left rear in primer
Here we are back to white again. Now we are ready for some color , and the insertion of the toys within the holes.