These are known as Neo-Wedge bulbs. The cap is used to diffuse the light and give it a particular shade such as warm, cool, amber, green etc. They are available in three sizes T3, T4 and T5.
If you need them new, you have to import them. Honda uses T3 size (Please confirm). Price of the old pieces are high due to the fact that these bulbs are taken out from switches like the defogger, fog lights etc which are themselves very rare and won't sell without the bulbs.
Alternatively, you can get the bulbs separately used in the these holders (T3) from a good electric accessories shops who sells industrial switches etc. I myself bought the bulbs (without the holders) from Co-operative market Karachi for rupees 2/bulb, there they are known as 12V miniature bulbs. You can later fit the bulbs in these holders with the help of a pair of tweezers. The caps can be reused on new bulbs but be careful with the plastic base as they are very fragile and can break if care is not taken.
A reference picture of the 12V miniature bulbs