Just got my Pre Plus about a week ago and needed to get a car charger. I found this one on Amazon and it works great:

Amazon.com: FosmonŽ Premium Quality Retractable Car Auto Charger for Verizon Wireless Palm Pre Plus 3G Smartphone: Cell Phones & Service

It's retractable, so there isn't bulky cord dangling down in the front of the car. I paired that with a Motorolla mini USB splitter so I can charge my phone and bluetooth at the same time:

Amazon.com: Motorola mini Bluetooth USB Y Adapter [OEM] SKN6222A for Motorola RAZR V3 / V3c / V3i / V3x / V3m / Moto Q / SLVR L7 / V8 / PEBL U6 / V6 / L6 / V360 / V190 / And all other Motorola L7c, L7e / L7i / L71, A1200 / MING phones which charge vi

I use the same splitter on the Pre Plus charger that came with the phone. 1 less thing to have plugged in and saves a little space.