Sometimes just changing old bubs for new oem bulbs brightens up the place. If you want a brighter solution, you can try LED bulbs. I tied red LED for the instrument cluster and the results were horrible! You can see the ones I tried here on page 6 (194RD):
http://www.toucanindustries.com/clientuploads/catalog/2005%20EUROLITE%20CATALOG(2of2).pdf
I removed them after 3 days.
I'm interested in a good solution too. Hopefully, someone else in here may be able to share a postitive experience.