Starsky & Hutch 2
if you think of the first movie as the prequel showing how they came together in 1975 - then you got the TV show with Glazer and Soul 1975-79 - then they could do a 2nd movie set post tv show in the mid 1980s to wrap it all up, showing S&H go their separate ways (which the final episode never showed) or getting back together whatever
itd account for Stiller and Wilson aging plus itd be a change to have S&H in the 80s and all the fun they could have with that (with the 80s being all popular cool now)...they could even have a present day scene at the end with S&H still roaming the streets (played of course by Glazer and Soul)
basically itd be the finale the tv show never got - just like the 2004 movie was the prequel the tv show never had (a little like Star Trek 2009)