IMHO you'd be better buying an Ortlieb water proof bag - I use one and just bungee it on. Superb and waterproof. Same concept as the BMW luggage roll but a lot cheaper. Touratech sell them, but you pay a premium for the Touratech logo on the side. Get them from a non-motorbike outdoor store i.e. Cotswold Camping.
No idea re Wolfman.
For every day commuting use use the Kriega waterproof bags. Excellent bits of kit.