That said, it is PERMANENTLY in Spain for 3 months, or a total of 183 days in a year.
Will you please provide a supporting reference for your claim (above) that there is a need to register if a "total of 183 days in a year" is achieved?
There is no such requirement in 38/2004.
There is no such requirement in Royal Decree 240/2007.
Where exactly did you get this idea from?
European Law on this topic is very clear. The period is question may be "not less than 90 days" and such periods are independent and consecutive. There is no cumulative element. It would be unlawful and would violate the Directive.
The only part 183 days plays anywhere relates to "fiscal residence" which is an entirely different topic.