According to the RAW, Heavy vehicles such as tanks are completely immune to fire from small arms and non-AT support weapons. But what about the optics? In all the mechanised warfare computer games I've played, the laser range finder and thermal sights of a tank are quite easily damaged by small arms fire, as are the smoke grenade launchers.

I would like to see some adjustment to the rules to allow for this, and maybe also to allow for smoke grenade launchers to be damaged (which currently aren't listed on the damage tables). Would anyone care to discuss this and/or suggest some variant rules?

[EDIT]

No takers? OK, here's my own shot at it.

On the table that shows how much firepower small arms and non-AT infantry weapons have versus vehicles, wherever it says No Effect, substitute the following:

1/2 FP **

Then add a note to the table as follows:

** -4 to damage roll instead of -2, highest result possible is "Main Gun Damaged"

On the vehicle damage tables, change the "Optics Damaged" row to "Random System Damaged"

Modify the Optics Damaged result description as follows:

Random System Damaged. Randomly select one of the following systems. Do not count systems which the vehicle does not have. Any result also requires a Bailout check.

Smoke-Launchers damaged: May not pop smoke for the rest of the game.
Thermal Sight damaged: No more night vision for the rest of the game.
Cupola Optics damaged: -1 to RT for the rest of the game.
Laser Rangefinder damaged: -1 FP for the rest of the game.

N.B. - A "Main Gun Damaged" result can be considered to represent rangefinder and optics damage more serious than the above.