Not really off topic, but who know where it goes...
If you fit, for example, a new speedo, as you are cool as sh!t and want a custom dash, where do you stand on the oddometer front? It's illegal to tamper, does that make it illegal to replace? Since the new one will probably say zero.
What if the actual speedo broke and needed replacing. It's not like you can set it to the right milage...