Can anyone help with seat adjustment? I've spent ages trying to get a comfortable position - lumbar support is okay - not great but manageable, but whatever I do, the seat squab itself is always too low for my legs - a gap of several inches. It is a bit like sitting on a bench and fine for short trips but I don't fancy anything lengthy. Mention is made elsewhere and on a very old post about raising the front rails which might solve the problem - is that something easily achieved on the Mk3?