I got one of these:
Wifi OBD2 OBD WLAN WIRELESS Diagnostic | eBay
This is the UK site but there are loads of these for sale.
Would I get one again, definitely. You can unplug and put in any car, have the same set up here in my Civic Type R. Even if you just want a code reader, having it on your phone is great - can connect to the internet for more info on errors. You can use it just on the phone, the fact it also displays on my double din is a bonus.
Haven't tried the race track yet, but you can select any road etc off google maps.