[s-cars] portable air compressor recommendation

[Lee Levitt]

Turns out my 17" wheels & 245/40/17 tires won't fit in the 
wheelwell of either my B5 A4 avant or my '99 A6 avant without 
being flat. So I'm looking for a recommendation on a DC powered 
air compressor that I can carry with me for autocross and the rare 
spare tire inflating.

Ideally I'd like one that combines both the air compressor and a 
spare battery pack (for jumping cars with dead batteries). Harbor 
Freight lists one, Sears has another, both in the $80 range.

Does anybody have BTDT? Specific recommendations on other units to 
consider. Speed, noise, price are the three concerns, in that 
order...

Thanks,

Lee