Great question: Click here for our most up-to-date hardware recommendations as well as purchase links.
Dash no longer supports WiFi adapters. After spending a lot of time working on support for WiFi adapters, we've determined that they just won't provide the experience we're trying to create. We apologize for this inconvenience.
If you're still wondering which devices to buy, here's a bit more information on why we recommend the units we do:
Many but not all of the lower-priced generic OBD units will work - however, they almost always have poor or missing documentation. Some devices work great with most cars, and others won't work at all. Some options work with most cars, but won't work with certain vehicles.
The producers of low-cost generic hardware are more likely to change the hardware without notice (and they have done so on occasion) so it's harder for us to ensure that they'll be working well. Also, almost none of them have a sleep mode, so they will drain your car's battery if left plugged in for more than a few days without driving.
Also note that Dash doesn't support USB-based OBD adapters, and that the Android and iOS versions of Dash have slightly different hardware requirements. In particular only MFi-approved Bluetooth devices are compatible with iPhone which limits the number of compatible options.
Be sure to read carefully, and send an email to firstname.lastname@example.org if you have any questions.