If your are refering to the plenum being a large box say for air mixing the answer is no. you should have filter in return side however be sure you have access.
Recessed mounted is inside a box with 1 side open, have louver then mounted inside the ceiling facing the opening downward. While surface mounted is directly screwed on the ceiling.
It is mounted directly to the starter.
The difference between flush and semi-flush mounted ceiling lights is that one of them can be mounted on the ceiling and the other one can be mounted elsewhere.
There are four motor mounts. One directly in front of the engine is mounted to the carriage and has black rubber dampening, One directly behind the engine also mounted to the carriage and with rubber dampening. One on the passenger side directly above the axle mounted to the body and one on the drivers side attached to the body and transmission.
The starter solenoid is mounted directly to the starter.
Depends what part of the country you live in. Probably in the range from $2,500 to $5,000.
Typically, the thermostat will be mounted on a wall above your return or on wall directly across from return. The thermostat needs to be near return to measure air temp going back to your air handler to determine when the temp setting has been satisfied, then the tstat tells the system to turn off.
The vapor canister is mounted on the firewall of the Honda Civic. The MAF sensor will be mounted directly to the let of it.
Mast system
Royal Canadian Mounted Police... The assumption I'm under is that 'Mountie' comes directly from Mounted.
A ductless air conditioning system is exactly what the name implies. An air conditioning system without ducts. The air handler is usually mounted on an interior wall or ceiling.
A starter solenoid on a Chevy El Camino is mounted directly to the starter.