[Kevin in NJ]

They are fairly important.

They keep water from soaking into the engine. Probably not such a problem since many are only driven on sunny days.

They channel the air to keep the engine area cool.

The are a major ground path from the grounded frame to the engine. So be sure the tabs are clean of paint around the bolts. Keep in mind various remedies that are to 'fix' the A actually defeat the original ground paths.

Without them you are more likely to have funny electrical problems and funny heating problems. Keep in mind a bunch of little issues can add up to difficult to troubleshoot problems on the road.