Once the top is wet, apply either a designated fabric or vinyl cleaning product or diluted all purpose cleaner which can be used on either material and allow the cleaner to dwell.
Work the cleaner in with a soft bristled all purpose brush that can be used alongside a normal shampoo solution.
For stubborn areas with ingrained dirt such as bird droppings, tree sap and algae reapply the cleaner to affected area and work in with either a stiff bristled detailing brush or a nail brush, then brush over the area with the soft brustled all purpose brush and shampoo solution.
Thoroughly rinse off the top ensuring all cleaning product residue is removed. Lightly rub or pat the top dry with a large microfibre drying towel.
Carefully vaccuum off the converible top with a soft brush attachment to remove any small pieces of dust or lint.
If possible move your vehicle indoors or to a more sheltered area. Apply a designated fabric guard or sealant to the convertible top evenly following manufacturers guidelines for product curing time.
Use a damp microfibre towel to wipe off any excess overspray from windows and paintwork.
Once your convertible top has been properly cleaned and sealed, a regular clean with a soft bristled all purpose brush and normal shampoo solution should be all that is needed to bring it back to standard, simply reapplying a designated fabric sealant as protection diminishes.