Theres been a recent hack published in relation to MITM attacks on sd cards, so its certainly feasible, whether its practical is a different matter.
This is the situation as I understand it so far:
- Stock maps on new SD card doesn't work
- New maps on stock SD card doesn't work
- Theres a 4mb partition on the stock SD card we haven't read yet
I'm without the car to test this week, but will be able to play around identifying if there is anything on that 4Mb partition.
In terms of taking things forward there are a few scenarios:
- The 4MB partition contains a version reference, maybe the CID and the Map serial, possibly the VIN
- The 4mb partition contains the CID and some map reference, but no VIN
- The CID is coded into the car somewhere
- The CID is coded into the map files
- Theres something else we haven't thought of.
I'll root around the partition this evening and see what I can identify, but it would be useful to know if people have tried swapping the SD card between cars, that rules out 1 and 3 entirely. 1, 2 are going to be solvable unless they've used some insane level of encryption. 3 would require a routine we can hopefully access through VCDS to get the CID in there. 4 would probably be breakable, but is certainly beyond my capability unless its in plaintext.
Does this sound about right to people?