Although the options are growing, the Mac market for GPS navigation software with GPS and turn-by-turn directions is far less mature than the market for such solutions in Windows. With
VMWare Fusion's support for linking your MacBook or MacBook Pro's Bluetooth radio to a Windows virtual machine (including your Boot Camp partition running as a virtual machine (VM)), you can use your Bluetooth GPS receiver with Windows navigation software.
All you have to do to enable the Bluetooth support in a VM is find the appropriate USB icon for the built-in Bluetooth radio in the VMWare window frame, and activate it on the VM. The icon will turn blue to let you know that that the Bluetooth radio is now linked to the VM. I
posted a quick demo of Streets & Trips detecting and using a Bluetooth GPS receiver in a VMWare session on my blog.