Lewbud - I would like to see what resin parts you got. I didn't look for them but don't recall if I've ever seen any. One thing about the Studio27 PE - on the hood of the car is a grill that is in the PE set. It has a different curve to it than the grill on the car's hood. I'm getting to the body of the model now, so I will have to deal with it.
Keavdog - The AK engine grime is not branded as a wash. It is product # AK082. It is a thinned paint, having some large and heavy pigment particles in it to give some grimey texture. If you thin it out, the heavy particles separate and you only get a color change, like a wash.
The guitar string is a #46 (0.046" diam). It has a core wire with another wire wrapped around it. I bent it over different size rods to get the smooth bends. It will hold its shape after bending.
I've finished the wheels and will post pics soon.