There are several "companies" who do this so it's not impossible

I've never brought in a Harley or anything else from the US - but I do have a US spec Moto Guzzi that came with me from the UK via Germany, plus another Bike that was never sold here and came from HD-DE.

Bringing ANY vehicle in normally has some paperwork. Mostly red tape. red tape means official stamps - this means time&money generally too.

It'll need a TECHNICAL specification document. If it's a Euro Spec vehicle this is easier as HD-EU (and others) homologate in Germany and one of the places to get said tech document is TüV Rheinland(Iberica) in Madrid who run a lot of the test centres (in Madrid anyway).

If it's already on the EU database - about €150 was par for the course, it may be a bit more now. If it's come from Germany and has the German tech document - this is plain sailing - basically they simply punch in the German homologation number and out comes a Spanish version. ime HD-EU are very good at helping - I have a Buell (which is HD) I bought with me from Germany. They sent me the specs FREE.

If not you'll need to pay to get an engineers report (not a mechanics). This is a must as the details are specified on the registration papers and are what the test centers test against. Includes permitted tire sizes etc. From experience of a mate who imports classic cars, expect this to cost a bit! - I've seen as high as €1000 quoted.

With this you need to have the vehicle inspected at an ITV center, to get a numberplate. This generally is just one MAIN office in each province - a PITA if it's not close, as you'll probably have to trailer it there as it has no numberplate (so no insurance).

Depending on the guy testing (really the top bod at the test center) it may well get rejected if it does not have EEC spec lighting and/or km/h speedo. My Guzzi had issues with "DOT" spec lights BUT was accepted as it was already registered in another EEC country. I believe they also now are HOT on "e" marked exhausts. If you mange to get it through without "e" marks,make sure it's noted on paperwork or you can have trouble at subsequent ITV tests.

VAT - if it comes from the EEC make sure you have a VAT document - otherwise you'll have to pay it (again?). This was on declared vehicle value - but I'm lead to believe it may have changed to the same base as registration tax - ASK. be warned - I had to do this with the Buell as the "gestoria" screwed up. You just get a letter from Hacienda - saying PAY UP. MAKE SURE shipping is NOT included on the declared value receipt.

Registration tax - This applies to all sales (inc local), new or second hand, so there's no way out. It's a value based on cc and age. The price you paid has no effect. NEW bikes in Spain are all going through an eco-rebate process. Old bikes donut get this - and the tax is going up step by step (yearly). On a new model it could sting a bit.

All this said - a lot of grey import "dealers" have ways of getting US spec'd bikes through. I've just bought a US spec Softail via a "dealer". Has non EEC lights and MPH speedo.

I've been here a while and simply couldn't be bothered to do the leg work. I've always used a "gestoria" to do all paperwork. I did do the Guzzi tech document legwork myself. It was 2 days work. If you do it yourself (fine if you are happy to do so) - you'll need patience and a reasonable grasp of Spanish. My missus is Spanish so I have an "edge".

Look on www dot motos dot net for used bikes close to you - also is used by grey importers.

I can recommend grey importer www dot bigirons dot es - did me a good deal

Some more details

Costs based on cc (in €)

Hasta 50 c.c. …………………………………. 600
De 50,01 a 75 c.c. ……………. 750
De 75,01 a 125 c.c. ……………. 1.100
De 125,01 a 150 c.c. …………….. 1.200
De 150,01 a 200 c.c. …………….. 1.300
De 200,01 a 250 c.c. ……………… 1.500
De 250,01 a 350 c.c. ……………… 2.200
De 350,01 a 450 c.c. ……………… 2.700
De 450,01 a 550 c.c. ……………… 3.000
De 550,01 a 750 c.c. ……………… 5.000
De 750,01 a 1.000 c.c. ………………. 7.500
De 1.000,01 a 1.200 c.c. ……………… 9.500
De 1.200,01 c.c. y superior cilindrada ……… 12.000

percentage of above based on age

Hasta 1 año …….…..…..….….....................…. 100
Más de 1 año, hasta 2 …….....…….............… 84
Más de 2 años, hasta 3 …….....…..............…. 67
Más de 3 años, hasta 4 …….....…..............…. 56
Más de 4 años, hasta 5 …….....…..............…. 47
Más de 5 años, hasta 6 …….....…..............…. 39
Más de 6 años, hasta 7 …….....…..............…. 34
Más de 7 años, hasta 8 …….....…..............…. 28
Más de 8 años, hasta 9 …….....…..............…. 24
Más de 9 años, hasta 10 …….....…..............… 19
Más de 10 años, hasta 11 ….…......…..........… 17
Más de 11 años, hasta 12 ….…......…..........… 13
Más de 12 años ...............….............................… 10

You pay TAX on these values

Add an administartive fee of 70,80 euros

Pinched these costs from a Moto Guzzi forum here in Spain.

Hope it helps.