wilmot i recently fitted bi-xenon to my motorbike. superb conversion, well worth doing. gives the vehicle a whole new modern look as well as improved light. not from ESP, but i looked at several different suppliers and the parts look to be identical.

tabetha anything higher than 55/60W in an H4 headlight is illegal. the legality is based on the power, and hid use much less than halogen for a brighter light. they will not be properly legal as they are not validated in combination with the lenses of an old headlight (even if the kit itself is e-marked - although it is usually only the ballast that is)

not a big deal in uk, as long as the beam pattern is satisfactory it will go through an mot and nobody will ever pick it up. it's not the same in all countries though. my german biker mates were jarred that mine was so good as they could not do it