Re: small 12v. air compressor in trunk for blowing up trike tires ?
Got a 'Wal Mart' special and a plug kit. Fixed a flat rear tire at Yellowstone last year, and a front tire on the Tri the year before in Nevada. I have it, the plug kit, a small jack and some other tools in an old briefcase I kept in the trunk Only used up 2" of floor space. Now in wife's Tri, not much room in my Freewheeler trunk.
Hint: it takes a L O N G time for the little thing to blow up a rear tire. If the bead breaks you are out of luck, they don't produce enough air to reseal the bead.
Another Hint: Like Mike said, a road assist. card and a high limit credit card are a must on long trips.