Just a short photo update on how I installed the LoPresti 28v HID ballasts for those lights.   All four done now.  Quite exceptional.  Existing wiring used, I simply transferred the connectors from the old lamps to the ballast wiring.  Click bonds used to hold the 4 ballasts to the forward spar face (no holes involved anywhere).    A template provided guides to place the clicks bonds.   The adhesive material sets up in 5 minutes so I was pressed to get 6 in place inside the leading edge and lost one of the bonds but two will hold a ballast properly.  The bulbs are D1S with integral igniters.   There is not a space problem.  If I had Audi projectors and the 28v ballasts I might be tempted to go that route but this was an easy drop in with no re-work.   There is a [200Hz] frequency to the bulbs but it is very feint in the radios.  So far, I am very pleased with the results.  While it took me a few days to gather the pieces, if I had to do a second one, I think it would take less than a day.