Musikbyrån provides an update on what all the guys from Bad Cash Quartet are up to: http://musikbyran.blogspot.com/2007/06/bad-cash-ynglar-av-sig.html
To summarize: Martin Elisson and Adam Bolméus are in the band Family Romance; drummer Jonas Lundqvist is working under the name Jonas Game and will have a single out on Sincerely Yours soon; vocalist Martin is also in the band Hästpojken with Pop Lars from Broder Daniel.