My initial thought was just to get it cleaned up under the hood, but after seeing yours I think it is probably more trouble than what its worth.
You can move the solenoid down low in the engine compartment where it's less noticeable. I mounted mine at the lower hole for the battery tray. Screwed in a 5/16 (?) bolt through that hole from the wheel well to make a stud to mount the solenoid. That point is now the main ground location for everything including the battery (-) cable.
Jason, If you put the battery in the trunk, I recommend the cable and the circuit breaker I referenced in my Showcase Post. Mciah