Mice taking over inside- HELP??

[disasterlady]

yup, they are winning... anyone have any idea as to how these critters could be getting in my cab? They have built nests on top of the AC/blower fan... gotten into my fan, nested inside the console, nested in the body work behind the plastic trim in the back and I trap about 1-3 of them a week INSIDE the VX! I've had them scurring around as I am driving along, even on the outside running up and down the side of the windshield, even had Woodrats nest on top of the engine with a pile of acorns left in various places prompting me to have to leave the hood up when I park on my carport. We have "Hantavirus" infected deer mice in this county, so ...

I keep the air intake vent on "recirculate" rather than "outside air coming in", I have torn off the cladding and put screening over the air pressure vents under the rear side cladding. I have put steel wool around the hood hinge/cowl openings as I saw one crawling under one time as I was driving down the road. I've tried Peppermint Oil and Moth balls. I spotted one coming out from under the side plastic trim at the bottom of the floorboard in front of the back seats where that little dip in the carpet is and put steel wool there, but am afraid I just blocked it from getting back out! It went crazy and ended up going up under the dash and later I heard gnawing as it probably was trying to chew it's way out. I took a UV light and found urine spots coming from my hand brake enclosure over the gear shift console. I have hesitated in getting those sound repellants as I have heard they don't work.

ADDED this EDIT 4/12/2012:
I am ALLERGIC to cats

I heard of someone who got a SNAKE which got up in the dash and they couldn't get it out, which leaves to all kinds of exciting Samuel Jackson scenarios.

I have traps all around the outside and inside... live in a rural area near creek and woods, so I could trap till eternity.

There are 2 huge Great Horned OWLS and several Red Tail HAWKS, COYOTES, wild FERRETS ( my favorite!! ) that live around here and they can't keep up with the rodentia.

So any ideas as to HOW they could be getting in?