I have Volvo s40 and its ballast is failed and want new one. I found this website it provides the same product that i need and price is also good but i need few more suggestion that it is right or not. I am sharing a link of this website https://xenons4u.co.uk/al-1307329209...t-ballast.html

 

the thing I do is find the volvo OEM part number from a dealer store or VIDA etc then go search on that part number. Simply google "volvo 31214562" and you'll find the linked site as well as a lot of others to compare prices, suppliers etc. Check out the dealer stores as well to look for added details like applicable models/serial numbers etc. The bigger sites like Rock Auto and Volvo specialists like IPD or FCP also do a good job with helping you to match the correct number to your specific year and model

 

For parts like this, I always check eBay (not sure how big the auto parts section of eBay in the UK is though). For "binary" (either works 100% or doesn't work) parts like a ballast, it's a good way to save a boatload of money.