Mice in Suburban - help please!

[wiscburb]

Hi everybody, newbie here...

I recently purchased an 89 Suburban that sat on a farm over the winter. Drivetrain, body, etc. is all great, but there's a little problem -- mice took up residence in the truck while it sat on the farm. The problem of course is the smell. Strangely, I can't find much trace of them in the interior of the truck, which is basically pristine. Here are the clues I have discovered so far:

• Mouse urine and a couple of droppings on some documents in the glove box; also, a urine stain on the rubber passenger floor mat
• A mouse nest inside the tailgate, on the left end (discovered it when I pulled off the inner tailgate access panel)
• A likely mouse nest (soft lumpy area) between the fabric and foam of the headliner, above the driver's head, with 2 holes in the headliner fabric nearby
• A terrible mouse urine smell when I turn on the heater; also got a few fuzzy particles out of the heater the first time I ran it
• Particles flew out of the rear A/C unit the first time I turned it on as well. When I went back there, it looked kind of like ground-up styrofoam
• And finally - a dead, intact mouse in the driveway, under the rear driver's side door, which was NOT there before I parked the Suburban in my driveway.

The thing that's missing is any evidence that the mice ever spent time around the interior -- seats, floors, etc are all clean as far as I can tell. I tried using a black light to locate the urine and didn't find any.

Here's my theory -- please let me know if you think this is plausible... I'm thinking if a mouse got into a rocker panel through a rust hole, he might be able to run up into the cowl and build a nest in the heater box. Then maybe the mouse could run through the rocker panel again, into the body in back and into the tailgate somehow. Then maybe the mouse could run up inside one of the posts between the windows and find himself in the headliner... Plausible? Are there any blockages along the way that would prevent our little mouse from doing this?

My thought is that the mouse couldn't get from the tailgate into the cabin because the access panel was sealed up tight -- couldn't get from the heater box through the heater core into the duct work -- didn't care to jump down from the headliner. Would that explain the circumstances? Apparent lack of urine except for in and under the glove box/dead mouse under rocker area/urine smell when heater runs? I don't know what to think about the styrofoam...

Lastly... Any suggestions on how to go about clearing all this stuff out? I hate to just start disassembling the truck willy-nilly with no game plan.

Thanks, VERY MUCH, in advance!

-John