Here you will find the necessary information about the conditions is not right at the beginning of the registration and updating process. I wondered why I did not hinkriegte register and update on my existing TomTom account. After 30 minutes searching and trial and error to TomTom, I have found the info that you need a separate account for every TomTom device (I have naturally tried on my existing account of the old TomTom Navigeräts). Sorry, TomTom - such information belongs to the beginning of registration, not somewhere in the FAQs.
When I had finally done it and wanted to install both updates offered, only worked one. For the second update I received in three attempts to point out that is a fault in the device. I gave up after 1 hour total exasperation, all packed together again and sent back. Never again a TomTom device, in which I must act on the TomTom website somehow.
For the actual use of the navigation in the car, I can therefore give no indication at all. I do not know how good or bad that is! For me, TomTom has done.