The Engineer has two possible career paths: one side of his skill tree is filled with vehicle support equipment, and the other is obviously skewed towards anti-armor capabilities. If you've already read through our beginners guide to 2142, you know that we recommend the EMP mine as one of the first things to unlock - which is the first in the anti-armor line of equipment. Looking further up the chain, you'll see the improved repair tool (the DysTek Repair v2.0), and the II-29 Motion Mine unlock.
On top of those, you'll find the anti-aircraft weapon system - but we think that this is virtually worthless because of 2142's already-weak hoverjets. If only this were available against Battlefield 2's uber-jets, we'd be singing a different tune.
While the improved repair tool gets automatically equipped when you select the Engineer class, the two sets of mines need to be selected and dropped into your kit. Serious vehicle hunters will want to do this straight away, as the disabling EMP mines plus their explosive, tracking cousins make for an extremely effective combo. Better still, mines of the future are smart enough not to go for friendly vehicles, so go nuts when you are laying them down - especially around strategic points that you want to protect. You'll rack up kills without even realizing it.