The best economical and quick improvement I chose was using the most powerful Halogen bulbs.
Be aware that the 200% brighter halogen Bulbs (GT200) will burn out within a year if you drive a lot at night. If that’s a concern for you then you may want to use the less bright 150% bulbs ( X-tremeVision 150) which should last twice as long.
Since I dont drive this car often at night I chose the GT200 as I’m happy to replace them again if they burn out due to the relatively cheap cost.
The OSRAM Halogen Night Breakers are also good Bulbs but when I looked up the price, they were considerably more than the Philips, so hence that’s why I recommended the Philips Bulbs.
Prices might be different (Cheaper) in your area for the HID conversion and price difference between Philips Vs OSRAM bulbs in your area may not exist.
EDIT UPDATE = I just noticed that OSRAM now has the brightest halogen bulbs on the market with their new brighter 220% H7 Halogen Bulb called “Night Breaker 220” and the price of these bulbs seems very competitive. I will defiantly consider trying these out next when my Philips GT 200 bulbs burn out.
But due to the GT200 still being relatively cheap I dont know if the extra cost of the ORSRAM 220 is worth it, since there may not be any noticeable improvement over the GT200.
$31 USD upgrade for halogen vs $370 upgrade for HID
Price examples are:
GT200 halogen H7 bulbs = $31 USD (carbulbsdirect.com) including delivery at Philips RacingVision GT200 H7 (Twin) | Car Bulbs Direct USA or $32 USD (powerbulbs) from this website Philips RacingVision GT200 H7 | Twin Car Headlight Bulbs | PowerBulbs US
I have bought many bulbs from the powerbulbs web site and can’t fault them, but I have not bought anything from carbulbsdirect web site so I cant add any comments on them although I suspect the same company is using both these websites.
Last time I bought something from powerbulbs.com I just googled discount voucher for their website and found a voucher that got me a few dollars off so you may be able to purchase these for about $28 USD if you can find a working voucher.
Retrofitlab HID KIT= 300 Euro ($317 USD) Volvo V50 04-12 bi-xenon headlight upgrade kit for halogen projector h which does not include shipping which is another 36 euro ($39 USD) shipping bringing it about $355 USD in total and that that’s not including the SKBOWE kit that you need to build costing about another $15 USD making the grand total to about $370 USD.
Note = The P1 low beam lights are the worst I have come across in any car. Whilst the Brighter halogen bulbs will make some improvement over stock, the improvement will not be anywhere as great when using these brighter halogen bulbs in any other car. I have used these brighter halogens in 3 other cars and the improvement is huge (great visibility) but in the P1 the improvement is less due to the sh*t low beam base line that these cars have.