Source: p 2 of 2, Relational Possessives Such as “Him” and “Her”, by Neal Whitman BA PhD
Foreword: To differentiate the two nouns surrounding of which, I replace the original quote's:
'car' with 'part' (abbreviated to P) and 'windshield' with 'whole' (abbreviated to W).
Sometimes the idea that inanimate nouns don’t have possessive forms shows up in a more specific claim: That the relative pronoun “whose” cannot refer to an inanimate noun. This is the idea that a phrase such as
“[1.] the W whose P got cracked by a piece of gravel”
should actually be phrased
“[2.] the W of which P got cracked by a piece of gravel.”
As I wrote in episode 108, “‘whose’ is the only English word we have to refer to inanimate antecedents. Perhaps someone will invent a new word for this purpose, but as of now we’re stuck with ‘whose.’ ”
Consider 3 defined as follows. Then I can tolerate that 1 = 3.
3. the W, the P of which got cracked ...
But how does 2 = 3? 2 seems wrong because from Definition 1.0, of expresses P as a part of W. So must P precede of which, as in 3, but unlike 2?
George Washington's 1789 Inaugural Address exemplifies the syntax in 2:
[4.] Among the vicissitudes incident to life[,] no event could have filled me with greater anxieties than that of which the notification was transmitted by your order [...].
I didn't understand 4 until I rewrote the preposition + relative pronoun:
5. [...] no
event could have filled me with greater anxieties than that [
event] [,] the notification [of which] was transmitted [...]