Any ideas where to buy a good (cheap, <$30) OBD-II to USB cable?
Of if you can recommend a good wireless ODB-II connector (even though it would cost more), I’d also be interested!

I’m looking to do some live data fetching from my G.

 

Osiris Cipher Cable

 

Although more than $30, another forum member is using for his G37's carPC:

OBDLink Multiprotocol OBD-II by ScanTool FREE SOFTWARE: eBay Motors (item 230470146696 end time Jun-02-10 1655 PDT)

Here's a less expensive option, but I don't think anyone here has tried it yet:

http://www.amazon.com/Crescent-OBD2-.../dp/B001MT0XPK

 

I bought the OBDLink 2.0 w/Bluetooth along with ScanXL directly from Palmer Performance...coupon code 'mp3car' for 15% off...the combo package price plus coupon made it pretty reasonable

PPE Online Store

 

I have the OBDPros USB cable, cost $70. Lets me see OBD/CAN traffic at pretty much full speed.

For <$30 you get what you pay for such as:

1) Slow bandwidth and data updates (meaning you'll miss data passing on the bus and you'll get slow sensor reads if you're lucky, "DATA ERROR" and "BUFFER FULL" messages if you're not).
2) No CAN compatibility (2008+ cars have CAN; this provides a LOT more data than OBDII alone)
3) Cloned hardware yielding incompatibility with certain software (non-upgradeable firmware, old firmware due to cloning of old chipsets like ELM 1.1/1.2).

If you still want a cheap bluetooh OBDII device, check DealExtreme. I got one for $54, shipping took a month though. This device isn't good for anything more than checking MIL's because even though bluetooth can theoretically do up to 1Mbps, this device doesn't want to switch to anywhere near useful speeds. It cant keep up, buffer fills up and it chokes; this is for full CANbus monitoring.

Your other problem will be software; OBD2007 is nice but is pricey. You really need to know what you're planning on doing with the cable/data but if you just want simple temperature/MPH readouts you'll do fine with free stuff.