I need to buy some roof bars for my son's 3 door Audi A3. Its registered September 2010 so it's a 8P type, petrol. The variant in the V5 says "ACAXCF1"

The roof bars I'm looking at will fit a model with a chassis "FWD.8P1" but won't fit a model with a chassis "FWD.8PA".

How can I tell which chassis version is my son's vehicle?

Many thanks

Monty