I did fit a set of 100/80W in a Lada once, brilliant light and no-one kept
their high beam on when approaching me for a second longer than they had to
;-) However the major cautions are a) make sure the wiring can take it. I
wouldn't be surprised if the wires are rated fairly closely just to save
money. If so you may have to fit a relay and extra wires. b) they are
probably illegal. Now I don't care and I doubt that a copper could tell if
they did a roadside check but... and c) it's just occurred to me that there
may be plastic elements in the headlights which may not take the extra heat
eg. a diffuser like XMs have in the dip beam or plastic headlight
reflectors.

I've heard good reports of the 50% brighter bulbs from reputable makers like
Phillips for example although some people say they don't last as long.

I wouldn't recommend.  Speaking from experience, I did that exact same
thing about 8 years ago in a car I had and it ruined the reflector
plate in my head lamp casing.  The amount of heat produced from one of
those little f%$#ers is extraordinary.
I say no it.  Malc made a good point, try those 50% brighter bulbs from
Phillips...I've read the same thing, they are good, or go for a HID
conversion.  Will cost a bit but will dramatically improve night
driving visibility.
Dan

Chris,

I installed some super brights from halford as they were doing buy 1 get 1
free. Came in a gold box, top of their range. The light that is emmitted is
far more white than the bosch and other brands. Things do appear a lot
clearer. No heat problems and they pull the same current as normal ones.
A good buy if they are still 2 for 1. strangely good in fog.

Regards
G

problems that they might get or if they could fit higher watts bulbs.