Get ULEZ Exempt? Make Pre-2006 Old Car Compliant-Beating TFL to Get Car ULEZ Free Despite Rejection

My 1998 car was repeatedly rejected by TFL as not being ULEZ compliant but I kept going and resubmitting the same info over and over. Finally they have accepted that my car is ULEZ exempt and I don't have to pay to drive my old car in London.
If you have an older car it's worth checking as many cars that are pre-2006 should be compliant as their NOx emissions are below the limit needed for ULEZ. TFL claim that the car has to meet Euro4 standards but that's not true - it only has to meet the NOx part of that standard.
My 1998 Porsche 911 is now fully compliant with ULEZ and can drive through the zone without having to pay any ULEZ charges or fines. Stick that TFL!