Moving Abroad? Plan ahead and save car tax(es) on your LHD car!
Make use of the EU six+ month rule and potentially save thousands in (car) tax simply by owning a (LHD) car 185+ days before transferring residence to certain EU countries! There are several areas where taxes on cars both new and used gained:

1) Setting up a secondary residence (holiday home) within the EU
Keep your car registered at your main residence. Providing the vehicle is maintained and taxed in accordance with your main residence's legal requirements, that vehicle could be used and operated at your secondary (holiday) home usually for a maximum of 182 days (less than six months).

2) Moving residence (main home) completely within the EU
Normally any VAT paid vehicle owned by you for more than either six months plus one day or one year plus one day (country depending) may be transferred as a 'personal possession' to your new home without incurring additional local car taxes that normally apply providing you keep the vehicle for a further 12 months. Furthermore, one needs to apply for re-registration either within six months or one year (country depending) of permanently leaving your previous country of residence. Typically the local taxes that apply to cars are as follows:

3) Moving residence (home) completely to outside the EU
Normally any new and/or VAT qualifying vehicle may have its VAT refunded to you on proof of export of the vehicle from the EU. We would issue you with the required export customs document which needs stamping on leaving the EU and then needs returning to us for the VAT refund.

4) Below are links to articles which may be of use:

a) Moving abroad permanently and re-registering your UK registered vehicle abroad - General advice & tips - Q & A

Moving Abroad - Help ? (pdf) 

b) Here are documents from the EU regarding action taken against Denmark, Greece, The Netherlands and Poland related to restrictions imposed on the movement of citizens against EU Directive 83/183/EEC  and Article 90 within the EU via Car Taxes imposed:

Denmark & Greece 2003 (pdf) 

Greece, The Netherlands & Poland 2005 (pdf) 

These documents provide some insight as to the guidelines that exist within the EU when moving to other EU member states. 

4c) France - It seems that there are currently two initial levies are imposed on registering a car:
i) Environmental / Pollution Tax - CO² depending.
ii) Road Usage Tax - A one off payment in lieu of an annual road tax that exists in most other countries.

d) Here is a newletter of recent developments within Portugal

Newsletter - Updated May 2009
Foreign (GB) Registered Vehicles used in Portugal (pdf) 

e) Here is a link to enable you to self-calculate the ISV (vehicle registration tax - VRT)) in Portugal:

PT - ISV (VRT) Website

GUIDE:
Estado-Membro da União Europeia (EU member state)
Automóvel ligeiro de passageiros (car)
novo  or usado (new or used)
if used  - date of first registration
gasoline (petrol)  or gasóleo (diesel)
C.C.  / cm3 (engine size - cc) 
CO² g/km - emissions (combined as on CoC)
Partículas (if particle filter fitted then < 0.005 g/km per CoC)
Click "Calcular Imposto"
You will then see the various stages of the calculation.
The final amount is Imposto Sobre Veículos (ISV).
VAT is usually applied to this figure.

f) Here a general link into the EU website offering background information on VAT and Motor Vehicles plus further links.

Information on Community Law

g) Here is a link showing VAT rates in various EU countries

EU VAT Rates

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