I guess no one on this thread knows anything about cars. Lets just say that one of the cars that I own is a brand that is a favourite of tuners. The Germans are right, and MOT, MTI, LTA, etc all of them know nuts about cars. When the Germans sell you a car, the engine power quoted on their brochure is that of the engine itself. The dyno does not measure this, it measures the power at the wheels. The power at the wheels will always be less than the power at the engine. Engine power is lost going to the drive train on the way to the wheels. By the time it gets to the wheels, the loss can be up to 15% for manual transmission cars and 20% for automatic transmission. Therefore, when the LTA measures a German car's "engine" power using a dyno, it is actually measuring the wheel power. This number will always be less. That is why the Germans don't understand why LTA is doing this, other than as a money grab.
For example, a BMW 3 series with a 1,600cc engine will produce 100kW measured at the engine. But when LTA puts the dyno on it, it could be only 80kW at the wheels. So, in this case, LTA thinks that the Germans are cheating because the engine they think will produce more than 97kW, they will be in for a shock when they see that it only produces as little as 80kW. Furthermore, all specs of the car used in the brochures cannot be lies, or they open themselves up for lawsuits, and even worse, damage their reputation. If BMW sells cars with stated output of 100kW at the engine, and it turns out that it was only 85kW at the engine, their reputation lost is not worth the lies.
Its unbelievable that some govt agency collects billions in COE, road tax, etc. and yet knows nothing about cars.