A4 1.8T chip upgrade and filter

["Carl Dziuk" <cdziuk@saratogasystems.com>]

I live in the Bay Area (San Francisco) and would like some recommendations 
for reputable shops that would do the A4 1.8T chip upgrade (from 150 to 
190) and filter replacement.

Also, what does this do for warranty and general reliability, wear and 
tear, etc.

Thanks all.