It depends how bad it is really. I jet washed my S1's carpet while it was out as it was pretty bad in the foot wells. I used normal carpet cleaner and it came up mint. Be careful not to get too close though as you can easily damage the pile with powerful ones.

If its not that bad, just use a wet vac and some decent cleaning fluid.

Not sure if the escos carpet has sponge like matierial fitted to the inside, but if it does make sure its FULLY dry before you put it back or it'll get mouldy in no time at all.