"This is your rear-window heater." Is this a "your" with "typifying generic force" or is it something unique to marketing?

Solution 1:

"This is your rear-window heater and here is your electronic parking break."

This is not the generic “your”. You can tell this by the fact that the salesperson will address you as “you”.

In this context, the relative adjective/determiner implies a potential personal control over its noun.

You would be able to see this if they added “… and if you glance upwards, you will see your self-dipping mirror through which you can see your spouse.”

This personalisation is a small psychological device that you will/ are intended to subconsciously translate as

"And when I buy the car, this is my rear-window heater that I will control, and here, when I buy the car, is my electronic parking break that I will control."

The problem of which the salesperson was unaware was that you happen to translate “your” as the informal/generic “any example of”, as in

“Now, friend, this is your common-or-garden rear-window heater.” Something that a salesperson is unlikely to intend.

Granted, in some cases it is not easy to discern the difference but the generic "your" is most commonly used of objects over which you have, and are likely to have, little control:

"Now your average camel is a flea-bitten, obstinate bastard that will spit at you as soon as look at you."

and used in very informal contexts, often to convey "interesting facts" or personal, expert, knowledge from the speaker's life experience.

Did you buy the car?

Solution 2:

This is unique to sales and marketing, but the psychological device is seen elsewhere. It is part of a sales technique called the presumptive close.

The assumptive selling technique, also known as a presumptive close, takes place when a salesperson intentionally assumes that the customer has already said yes to the sale. For example, an assumptive statement from the salesperson might be "give me your credit card and I'll get the paperwork started."

The assumptive close works well because it comes across as professional and is used as part of an intentional sales process. To implement it effectively, you must have a clear understanding of the customer's needs and desires beforehand. If you have listened well and matched the customer up with the perfect product or solution for their needs, then there is nothing more to discuss with the customer, except for how they intend to pay for their purchase.

(from https://www.thebalancesmb.com/assuming-the-sale-3887432)

The car salesman is having you envision the car as your own as you are literally in the driver's seat. It is not in fact your rear-view mirror or your car; however, the salesman wants you to make a psychological shift towards ownership.

Solution 3:

This usage is not specific to marketing language. Instead, it is common to familiar usage. As Collins notes:

your determiner
3. informal used to indicate all things or people of a certain type: your part-time worker is a problem. _{TFD Online}

American Heritage (at same link) adds this note:

3. Informal Used with little or no sense of possession to indicate a type familiar to the listener: your basic three-story frame house.

So it is general and informal, with the nuance of something that is familiar to the listener (I would add "to the speaker", since it implies a special knowledge of the subject.)

Note that the above description does describe many marketing communications, but the usage is so general that there is certainly no cornering of the your market there.

Addendum

As I mentioned in a comment:

... the salesman may also be trying to position the vehicle as, somewhat proleptically, belonging to the prospective buyer.

Whether this is what you're reacting to I can't say (and that is beyond the scope of this site anyway). But it is certainly common for salespeople to do whatever they can to have you "try on" ownership of the object being sold, although the line between that and simply using your as a more familiar-sounding determiner is blurred and possibly not something that can be determined in every case.

Solution 4:

Here is the OED’s definition (along with a couple of usage examples) for the your that maps to the usage in Quirk:

B. adj. The possessive adjective corresponding to ye, you.
1. d. Used to designate a person or thing known or familiar to the person or people being addressed, or which is typical of its kind. Sometimes with derogatory implication. Cf. your actual —— at ACTUAL adj. 2b(b).
_{. . .
1978   Billboard 30 Sept. 48/4   Take your big stores for an example.
2010   J. STUMP r. P. Siniac Collaborators 66   Your Frenchman isn’t so prissy, everything cracks him up.}

However, what you are describing matches the OED’s definition at:

5. Belonging to or associated with any hearer or reader; one’s. Cf. YOU pron. 8.
_{. . .
1981   N.Y. Mag. 16 Nov. 177/3   As you walk through the living room, you almost have to catch your breath at the view of the lake and distant mountains.
1992   Hamilton (Ont.) Spectator 30 June c1/4   Letting the rope feed through your hands is the essence of rap-jumping.}

That is the possessive determiner form of what is known as the generic you.

So, I wouldn’t take it personally.

_{Source: Oxford English Dictionary (login required)}

Solution 5:

It is easy to imagine the same usage in a TV program about cars. So it's not a personal your. But it's not the same as Your average football supporter, either. It is an indefinite personal possessive pronoun.

Wiktionary has this as its sixth definition for you:

(indefinite personal pronoun) Anyone, one; an unspecified individual or group of individuals (as subject or object).

For example, "You can't always get what you want." It's not creepy at all.

If we can imagine Prince Andrew reduced to the rank of car salesman, it might go like this:

This is one's rear-window heater and here is one's electronic parking brake.

To my ears, this has exactly the same meaning as the OP's example sentence.