Have the same trouble since I purcheased hi tech Bosch wipers....one on
drivers side seems to get stuck under the hood and then snaps free...

There should be about 3/8" clearance between the stock
blades and the hood when the wipers are parked and the
driver's side blade is seated in the parking clips.  Since
the hood is OK, this sounds like the wrong arms or, the
blades that use an adapter to mate up with the factory arms.

Check and see if the driver's-side parking clips and rest
block are not bent or haven't been removed by a prior owner
who installed the wrong arms.  The driver's side arm 'snugs'
over a rest-block located pretty much in line with the
steering column.  The blade parks into a large bracket near
the center of the blade and a small bracket near the tip of
the blade.

Anco makes a blade refill for the C4; however, the correct
refill isn't a part of the "standard" Anco inventory in the
yellow box at the gas station -- it's an over-the-counter
item.  Parts person has to know what they are doing.

Although the price for GM blade refills seems outrageous
(IIRC, $25 a pair), I think they fit and last better than
aftermarket brands.

then why even respond ?