Yes, I am using MCP2515 transceiver with 5V. I use it with a voltage regulator. The baud rate I am using is 500kbps which is from what I have found that uses a Leaf.
The other question also applies what to do whit the car now? Is there a trick maybe to solve the already created errors (I have already tried to delete the errorcodes via OBD2 connector but they come back and also tried to reset ECUs by removing cables from battery for a few hours without success), or just bring it to the dealer?