Though still problematic to the inattentive players, this issue will be somewhat addressed in a future patch. As of August 05 2016 dev branch notes:
Aug 8 2016
Can confirm. Similar issues on Altis with the snakes and rabbits, has a pretty nasty overhead.
Jul 25 2016
@Lex @razazel, You are both correct. Seems at some point I had flipped of PIP for my main branch profile. That would make sense. Evidently I had expected a placeholder image, akin to review mirrors in vehicles.
Jul 13 2016
Confirmed, would appreciate a params toggle to delete vehicle spawned when the garage is open. Currently, only way to remove the vehicle is by another script, ex. to run a local script (if in mp) to detect a vehicle at the spawn point and delete it. Messy and expensive.
May 10 2016
Bad news: This is a duplicate report.
Good news: The original report has been assigned. http://feedback.arma3.com/view.php?id=21512
Edited to reduce text size, as well as adding suggestion to allow pilots to open doors, in consideration of solo-pilots.
This is still present and has not been reviewed yet.
ACRE is easily the most immersive mod I've played in the Arma series. Better than more vehicles, more maps, or more weapons, ACRE is the best.