Looking through the bits box last night, I found a load of wheels. Since I'm getting started on painting up all the Imperial Guard I have had laying around for ages, I thought I could make use of them to mobilise some of the heavy weapons. So... I present the Heavy Automated Weapons System; three lascannon making up a heavy weapons squad.
Stub axles on the wheels from plastic rod, square section plastic tube for the axles, lascannon from razorbacks. Quick and easy.
Okay, a bit too easy - I added a bit more plastic to the sides of the platform to make it look a bit more solid, and some front bumpers. I will add some stowage on the back and a light on the front, but basically that's it. All I need now is a single crewmember for the squad - I will scratchbuild his arms so that he's using a remote control like you get for RC cars.