Hello, I believe this issue may be related to the following bug fix in DayZ 1.18:

• Melee damage was dealt in the direction the camera was facing

You can no longer target a car engine with any melee weapon (one or two-handed). You need to look down to target the engine, however the game forces the damage to apply to whatever is facing directly ahead of you (windshield).

It is often useful to be able to destroy a car with a melee weapon. Hopefully cars can be excluded from this fix so this functionality can be restored. Thank you!