Recently new version of analog fast-SPICE simulator AVOSpice has been released. Verilog translator was added to the simulator so AVOSpice processes netlists which include Verilog A models (similar to BSIM3 and BSIM4). At first this version will be offered to customers for free on tne condition that they perform beta-testing using their netlist. This special offer is time-limited.
You can inquire this version from the site www.avocad.com (in 'comments' field mention that you need version with VerilogA models support)