Bright interior lighting

Hi, I’m disturbed by the funky interior lighting from my golf3. I just wanted to replace it for a few white leds, but as I had to read in various foren and above all here, luxeon leds at most get the “light power” of the standard built-in 10W bulb. However, the temperature coiling would be a problem. Besides, they are not quite cheap. In addition, there are in various shops leds in soffitten-adapters, but I didn’t find any infos. how bright these are compared to the 10W bulb. Does anyone have any experience in this regard or tips on how to get as bright indoor lighting as possible? As I said, I’m only concerned with brightness, no colors, etc. Thanks already, Twirex