[dsfyu404ed]

I'd avoid anything with a speed written on the screen. I can't see an insurance company passing up the opportunity to screw you for going 5-over

[erobbins]

I turned off GPS on mine for that exact reason. If your speed is +- 10 mph the average speed of traffic, it's not a factor. Unless you're an insurance company, of course, and then it's a great excuse to deny a claim.

[jameshart]

speed can probably be accurately inferred from video evidence anyway.

[comrh]

I'm pretty sure new cars are storing this information anyway.

[dsfyu404ed]

Insurance companies will need to jump though hoops to access that data in a fender bender where you still have possession of the vehicle. If you provide it (in a dash cam video that's evidence that you shouldn't pay) you're giving them an opportunity to deny the claim right there. There's also a lot of cases where traffic is doing 20-over and 20-25 over is criminal in most states

[jessaustin]

If you have Progressive Snapshot or a similar device, that's storing driving data, but which cars do so by themselves?

[bri3d]

Almost all modern cars have an Event Data Recorder as part of the SRS/Airbag system which records snapshot data in the event of a deployment. Here are some NHTSA standards for EDR storage:

http://www.nhtsa.gov/DOT/NHTSA/Rulemaking/Rules/Associated%2...

Here's a list of vehicles supported by one consultant's forensics software:

http://www.rimkus.com/uploads/pdfs/Event_Data_Recorder.pdf