Replacing Toyota Echo Rear Side Marker Lights

I had to do a ridiculous amount of research to replace some running lights on my Echo, which by all rights should have been a simple job.

Lesson 1:
At some point Toyota (during manufacture or maintenance) put a freakishly large W5W in one socket - now the socket doesn't hold normal bulbs securely enough.  The solution (thanks to the guys at Lordco) is to bend out the contact wires on the bulb - that provides enough tension to hold the bulb in place.

Lesson 2:
There are lots of little bulbs that fit the same socket as the W5W.  If you read online disussions, talk to the parts department at Peace Arch Toyota, or even the otherwise bright folks at Lordco, it is fine to replace W5Ws with any bulb you feel like.  These people will grudgingly admit that yes, there is a brightness difference, but not very much.  The 194 was a popular replacement suggestion, in spite of being only half as bright as the W5W.  WTF?  I don't understand why bulbs aren't labelled with lumens or candlepower, seeing as how that is the most important detail.

My online scavenging says:

• 194: 2 candlepower
• 168: 3 candlepower
• W5W: 4 candlepower

Lesson 3:
2003 Echo user manuals say you should be using W5Ws, but the dealership computer says 192.  I never found out what candlepower that actually is.  (Lordco's computer agreed with the user manual.)