TRDVILLAIN's method looks the better. Cutting a hole in the door might seem
scary, especially if it goes wrong but a drill with a hole cutter attatched will
pretty much cut through with no problems. Just remember to make a template
of the tweeter first and use a sharp knife to cut the vinyl around it before
using your hole cutter. Toyota did have tweeters fitted in the corner triangles,
....the picture below. Not really impressed by it..part No if your interested is:
86160-2B180, 86160-2B170, 67491-20330, 67492-20330 (THESE ARE SEPARATE
TWEETERS, LEFT AND RIGHT AND THEIR CORNER UNITS) ...I think, can anyone verify!