I have kept my Canadian-plated ST in Europe for the past 10 years. I'll confess up front to being a scofflaw in this respect, because the law in just about all European jurisdictions is much the same: You can keep a foreign-plated vehicle in a country that you are visiting for a finite period of time (typically between 3 and 6 months) provided that you are a bona-fide tourist using the vehicle for 'pleasure tourism' during that time period. Beyond that time limit, you either have to remove the bike from the country (or customs area, in the case of multiple countries that share a customs agreement), or properly import the vehicle, which means paying import duties & taxes, passing any required inspections, conforming with emissions & technical regulations, and plating the bike locally.
For a number of years in the early 2000s, I shipped my bike back and forth from Canada to Europe by air each year, but that was expensive and cumbersome, which is what prompted me to just leave the bike in Europe.
I live in Canada, and spend most of my time in Canada, and only use my European ST about 6 to 8 weeks a year. Each year, I leave it in a different European country. I arrange storage with a motorcycle shop somewhere who will keep it indoors. I don't ride in the same countries or same places year after year, I'm always going to different places... last year this included North Africa, the UK, and numerous western European countries. I don't have a residence anywhere in Europe, I stay in hotels when I travel. Insurance is easy to obtain, it costs about USD $60 a month for liability coverage, which is the only kind available for an out-of-continent vehicle.
Although what I do works for me, I wouldn't recommend it for someone who plans to stay in the same area. The original poster (
@McGrufus) stated that he purchased an apartment in Spain, which suggests that he will have a fixed base of operations. I don't think it's a good idea for him to try to keep a foreign plated bike at his home in Europe, because pretty soon, the local authorities (police, customs, whomever) will take note of that foreign plated vehicle being around all the time and they will get curious.
Given that the original poster has a legitimate residence in Europe, he would be able to register a bike that he purchases in his country of residence without undue difficulty (something I cannot easily do, because I don't have a residence in Europe). Used ST's are no longer expensive. I think it would be in his best interest to purchase a used ST locally, and register & insure it in his own name in his country of residence. It will cost him at least $1,500 USD to ship a bike from America to Europe, and likely about the same amount again to go through the process of importing it, homogulating it (lighting system compliance, emission compliance, inspections & approvals), paying duties & taxes, and so forth. For $3,000, he could buy a pretty decent used ST locally and register, plate, and insure it in a single afternoon with no headaches.
Michael
PS: The biggest potential problem associated with importing a North American vehicle to Europe (or vice-versa) is complying with emissions & lighting regulations. Although the vehicle might be exactly the same worldwide, the approval sticker on the triple-tree is only valid for one continent - and in many cases, it is impossible at any price to get approval to register a North American approved vehicle in Europe, or vice-versa. The vehicle manufacturers love this kind of paperwork headache, because it provides a great barrier to grey-market imports of vehicles.