[Imp]

As stated terrain does not provide any attack benefits however it does allow you to get close for an accurate shot or assault.
Woods are therefore good terrain for infantry to take on vehicles but there are a few key factors to success.

1) They need to swarm & this is made a lot more difficult since the change a few patches back that infantry need MP to assault.
2) While hand grenades can get the job done having a decent AT weapon makes success far more likely.
3) A suppressed vehicle is in trouble your goal should be to heavily suppress them as destroying becomes far easier or they may even abandon the vehicle. Hence the importance of point (1)
4) Suppression is detrimental to your units trying to deliver the kill shots, keep that in mind when rallying units they are the priority.

How to pull it off, quite a bit to try & achieve.
Attack it as many times as possible to cause suppression using the following guidelines & if possible hitting with artillery beforehand to suppress them.
1) If your AT weapons can destroy it from a side or rear facing try & position yourself so you can get a shot at it by switching firers & making the vehicle rotate.
2) Otherwise just fire to suppress initially your not hoping for a kill.
Keep hitting it then assault once suppressed so no shots & easier.
3) If you cannot kill it but get to retreat status cover its exit route (not easy)
It may bail out if not it will be attacked as tries to retreat.
4) This is one of those cases where staying put for accuracy goes out of the window after the initial attack swarm with everything you can.

So pulling it off
If adjacent look at your forces & plan your attack - keep in mind MP needed to assault & its suppress then kill. Also if an assault fails that's probably all that unit can do that turn.
Therefore use the W key to attack from adjacent & cause suppression, first squad is likely going to get punished & take fire but if it survives in good order can now possibly assault or often better to keep attacking with W let a fresh squad go for the kill.
Hard part is judging when to stop W attacks & go for the assault kill - tank main guns can cause suppression in multiple hexes making life difficult so try & keep that in mind & the fire away from your kill squads when attacking.

Make no mistake its a challenge now you have to reserve MP to assault but the odds are in the infantries favour entering woods infested with them is dangerous. Modern ERA in particular a tank can cost as much as a company of infantry.
So say 5 squads a tank if you can get position that's 2 dead tanks for say 10-12 men.

Note - Engineers equipped with high warhead weapons like flamethrowers demo charges need special care.
Not the best weapons to destroy a tank with but good at causing suppression possibly to multiple units - that means they can also suppress or kill your own units. This means they can actually do more harm than good in your main line.
If you have good intel they are good units to move in to block the vehicles retreat if you can pull it off.
High accuracy weapons so chance of hitting even if they have moved plus an attack in the hex still causes suppression (routing tank now in a flame hex).
Hopefully they are now in a position to suppress the next wave letting your front line shake off their suppression & regroup.
Flame weapons in particular including teams are very effective for giving you a breather if you manage to set a few strategic hexes on fire as they cause suppression.