Is there a model for package and bonding wires?

If it's for a Google MPW run, then the "package" is just WLCSP bump bonds on the top of the chip, and no bonding wires. If it's for a ChipIgnite run, then we'd have to work up some model for a QFN package; we have the wire bonding diagrams for it. Are there any open source tools that can generate a package equivalent circuit model?