I second the hardware cloth approach.

Another CRITICAL place to put the hardware cloth is around the rear cabin exhaust vents on a wagon (I don't know about sedans).

I had mice in my 940 Turbo... found about 4 babies dried up in the back... around the spare tire well.

Anyhow, I fashioned some hardware cloth screen covers that wrapped around the exhaust vents. These are on each side in the rear, in those little hatch areas. It's important that the airflow can still flow freely, since I think these help to keep the air pressure from blowing out the windscreen when you slam the doors. Also they assist in airflow when enroute.

But I think that's where the mama mouse got in to have her damn babies.

But not any more.

Slightly askew from the subject: Several years ago, the indy mech told me about another Volvo customer who came in complaining that his car was very sluggish and got terrible fuel mileage. Owner had changed plugs and air filter to no avail, without noticing the large dead rat stuck halfway into the air intake.
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We have met the enemy and they is us. [Pogo] S70 T5 cop car : Rough Rider suspension, Walmart fog lights, eBay speakers, ambiance by Pall Mall, trim by Le Duc d'Tape, 8-channel THD by OEM amps

After reading the other posts, I wonder if it was mice. They don't normally leave food laying around. Chipmunks, on the otherhand, do store food and love to live in houses and garages.
I like the idea of mothballs, they will help boost the octane too! At least that's what I was taught in high school.

Klaus
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98 V70Rawd(101Kmi), 95 854T(85K mi), 75 164E(173K mi)

Mothballs will not last long in your airbox, given the airflow through there. I like Spook's idea of hardware cloth, which will be strong enough to resist mice yet not diminish airflow too much.

Dear Steve,

Good a.m. and may this find you well. I would not use window screen material: mice/rats can chew through it. Rather, I'd use "hardware cloth". This is a steel wire-mesh, with the wires tack-welded where they cross. This can be had with openings from 1/4" to 1/2". It is too strong, for mice to gnaw through it. It is wide enough, though, not to be easily clogged. You can buy hardware cloth at hardware stores or Home Depot, etc.

Hope this helps.

Yours faithfully,

spook

Cleanliness, or lack thereof, has little to do with why mice are in your brother's garage. They're likely there seeking shelter, not food. I think your idea of a few mothballs in the bottom of the airbox is a good one. It's probably an even better idea for your bother's other two cars since the mice are probably still living comfortably in his garage. I'd also suggest setting a few mouse traps around the garage to rid the area of the little buggers.

It's my philosophy to do all I can to live harmoniously with God's creatures. But when one of the little bastards invades my space (my home or my car) all bets are off!

Jeff Pierce
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'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow