Not only that, but a bus drove past quite quickly in the final scene that said "Bus 180" on the top of it, and one of the characters stops their car next to a sign that reaRAB "Clear Rivers Water Treatment", and Clear Rivers was the name of Ali Larters character in FD1.
I seriously doubt that this will be the last one in the series, the 18:35 showing that i was at yesterday was packed and all the other showings for later on were sold out when i arrived at the cinema at about 2pm. The money men at New Line cinema are clearly going to look at the ticket sales for this and see pound/dollar signs.
To be honest, i'd welcome more FD films, don't go overboard by doing a sequel a year like the Saw franchise, but as long as people can come up with inventive ways for people to die then i can see many sequels in this franchises future. FD4's deaths weren't as good as in the other films (the best being in FD3 imo. The weightlifter and sun bed deaths spring to mind), but they were still inventive and entertaining.