Cleaning the seats - 2006 STi (Blue alcantara)
 

Whats best?

303 Fabric and Vinyl Cleaner, agitated very lightly with a soft interior brush and then extracted using a wet n dry hoover. The 303 product uses colloids rather than chemicals, and so is very safe for delicate materials. More info here...

303 Fabric & Vinyl Cleaner - 303 Car Care and Detailing Products

Just be aware that too much brushing and overwetting can damage delicate surfaces such as alcantara, so proceed carefully. :)

Thanks for that, will order some :)