You could try contacting Volvo dealers in Europe for a kit, but as they are required there, no one would need to add them. However, if a Volvo were brought to Europe from the US, they may need to be retrofitted. I am not sure how the EU handles importing US spec cars, but I think in general, its not easy to do.

You would need an adjuster switch for the dash, wiring harness, and the headlamps would require the adjuster motor (they are usually externally mounted on the housing. Check out Hella's website for more info on adjusters.

Installing HID into a non-HID headlamp is not recommended, despite what aftermarket companies tell you. For one thing, the reflector and lens are designed for the focal point of the bulb to be in a certain position, and for the HID universal replacement, that is not likely to be in the same place. So, you may get light, brighter in some areas, not in others. Another is thing is heat. A lot of heat. Halogens get hot, but HID's burn hotter. HID units from the OEMs are constructed with this in mind. The reflector is a metal "can" with a glass inner lens (shaped like an eyeball, sort of) The metal can tolerate the heat, and so can the glass. The trend today is a Bi-HID unit that switches a screen in the light path to create low or high beam.

I would be concerned with the long term durability of the unit if HIDs were installed, and you may not pleased with the performance, either.

In general, Volvo headlamps are very good performers, due to their safety reputation. How are your headlamps, appearance-wise? Are the lenses pitted, or cloudy? A replacement lens and/or disassembly and cleaning of the inner lens surface could improve performance. Pitted lens scatter light, and are not too expensive (100 bucks per) to replace. I would then recommend protective covers like those at www.xpel.com. I have used them for several years now with no stone damage and am pleased with nightime performance.

I would consider heavy duty springs from IPD to help keep the vehicle level, as well.