Reading multiple pots

Would this work or not even close?

Did you even try compiling it?

 if(Serial.available == 'A') //if steering wheel changed, do this using value above

Serial.available is the address of a function. It is highly unlikely that it will equal 'A'.

The code you had for reading data expects all the data for a packet to be between the < and the >. Sending data between the > and the < simply guarantees that it will be ignored.

could be sent. Then, when started and ended are true:

char ltr = ' ';
if(strlen(inData) > 0)
{
   ltr = inData[0];
   inData[0] = ' ';

   val = atoi(inData);
}

Then, ltr will be 'A', 'B', or 'C', and val will be the numeric value sent.