In my book, I argue at length that Romans 2:17-29 is not primarily an argument about salvation, but rather an argument about Jewish identity and vocation.
[Paul’s] conflict over the nature of Jewish identity comes to the surface most explicitly in Rom 2:17–29. If we take this passage at face value—and we will maintain that we should—it appears as a sustained contest over Jewish identity. The passage begins with a direct question about Jewish identity (v. 17), ends with a direct statement about Jewish identity (vv. 28–29), and is replete with arguments and disputes over terms relating to Jewishness. (p. 140)
The argument is set out in chapter 5 of the book:
The aim of this chapter is to conduct such a reexamination of Rom 2:17–29 in light of our claims concerning Paul’s Jewish identity. We have been maintaining that Paul neither accepts the conception of Jewish identity prevalent in the mainstream Jewish community nor rejects the value of Jewish identity altogether. Rather, in light of the gospel of Christ, Paul contests and redefines the distinct nature of Jewish identity itself. In this chapter, we will argue that Rom 2:17–29 constitutes a densely argued summary of this contested process of Jewish identity redefinition. We will demonstrate that the social setting presupposed throughout Rom 2:17–29 is the “mainstream” Jewish community, focused on the teaching of the Law in the synagogue. Paul is here seeking both to reject the mainstream Jewish community’s understanding of the significance of Jewish identity, and also to affirm a distinct, pre-eminent and theologically significant place for Jewish identity, informed by the prophetic Scriptures and, ultimately, by the gospel he preaches (cf. Rom 1:1–2). (pp. 142-143)
Thus the passage is not about soteriology, but about Jewish identity:
Furthermore, we have consistently maintained that Paul does not understand the distinct value of Jewish identity primarily in soteriological terms.
…
Here, we will see that a sense of divine vocation based on divine revelation is also fundamental to Paul’s contest over Jewish identity in Rom 2:17–29. Paul’s discussion of the Jewish “teacher” of Gentiles, therefore, is not merely a rhetorical device used to make a further point about Jewish sin or Jewish arrogance with respect to salvation. Rather, Paul is discussing an issue that is directly relevant for his contest over Jewish identity—the existence of a distinct Jewish vocation based on the possession of divine revelation. Paul is rejecting the mainstream Jewish community’s understanding of this vocation, and paving the way for an alternative understanding. Indeed, as we shall see in the following chapter, the Jewish teacher in Rom 2:17–29 can be seen as a foil for Paul’s own vision of Jewish vocation, which he sees fulfilled in his own apostolic ministry of preaching the gospel of Christ to the Gentiles (Rom 9–11). (p. 143)
The full details of the argument and further references may be found in chapter 5 of the book (pp. 140-194). The chapter is available from the publisher in electronic format:
Windsor, Lionel J. Paul and the Vocation of Israel: How Paul’s Jewish Identity Informs his Apostolic Ministry, with Special Reference to Romans. BZNW 205. Berlin / Boston: Walter de Gruyter, 2014.