We (NCR/CCR) always run ITR with ITS and I've only seen it be an issue one time, at Roebling Road May 2010. ITR BMW driver held up four ITS cars that couldn't pass and make it stick in a straight line but could pass (dangerously I might add) in T3, T4, T5. The driver of the ITR car should have let the ITS boys through because he was so far back in the ITR race it didn't matter.

All the other ITR/ITS mixings in the past couple of years have been fine.