Interesting Effect while painting (no pics)

Sadly I can't post pics of this cos my camera's gone up the spout (and I'm not so sure it'd show up on camera anyway).

I started by painting the shoulder bells ... they seemed the obvious place for me to start.

So I went to Halfords and picked up some car paints:
Grey Primer
BMW Titan/Titanium Silver
Plastic (Yellow) Primer
Vauxhall Mustard Yellow

The primer and silver went on a dream, BUT (and I don't know if this affected the result or not) I forgot to wet&dry the silver before starting with the yellow primer.

Afterthe first coat I noticed that the primer dried in a crackled pattern over the silver. I wasn't too deterred because I thought it looked kinda cool.
So I painted another coat of primer, added some more masking liquid then started on the Mustard Yellow top coat.

The top coat filled in the cracks, leaving an aged leather look on the areas of my shoulder bells where I hadn't masked it.

It adds nicely to the aged look and doesn't show up unless you look closely.

Is this because I'm using car spray paints or because I forgot to wet&dry the silver?

I think it is the only other reason is the paints are the wrong types to be layering. I used the same brand of paint - still got it - called the manufacturer who stated with alot of exterior or automotive paints you must let each coat "gas out".
Oddly enough I use this as a technique when weathering items sometimes, when the gator skin starts to "lift" from the lower silver layer, I simply help it along with masking tape wrapped around my fingers and gently tap the areas I want the silver to come thru. You must do this at the right time or it could ruin the piece and you'll have to start over. Heres a pic of my shoulder armor I used this technique on.