Different evangelicals will get off at different stops. I encounter some evangelicals who won’t get on a bus with the name “Mary” on it or near it. My own experience with these sorts is that they have reacted, justifiably, to Marian extravagances in their past or in the their family. Others are quite happy to appreciate a Mary who learned, as did Peter, that the vision of Messiah Jesus was revealing was one that required they surrender their political vision for a cross vision. Some high church evangelicals, on the other hand, are quite happy to embrace the historic center of the Church on Mary — including perpetual virginity and immaculate conception. Recently an editor of a magazine said he embraced those things because the Church has always embraced those traditions.
I'll have to go look it up again, but I recall that the doctrine of the immaculate conception only emerged during the Renaissance, and was formally promulgated in the 19th Century. Anyway, I'll be glad to ride the Mary Bus as far as "Mary is a great role model for Christians", and thereafter get off. The Via Media has its limits.
UPDATE: Related: Why so many evangelicals are converting to Roman Catholicism:
A major attraction of Roman Catholicism is the desire to belong to a church that is really, really big. Many evangelicals have acquired a morbid love of big churches. There is no megachurch as mega as the Church of Rome. A TV preacher might build himself an empire from an auditorium designed to look like a shopping mall, but that is no match for an actual empire, ruled by an actual monarch, from the Sistine Chapel. Both evangelicals and Catholics are attracted to theologies of glory.
(Hat tip) I agree. Additionally, there are many sectors of evangelicism which have a complete disdain for tradition -- only the new, the fresh, and the contemporary is valuable. It makes the church hip, but it also gives people a sense of rootlessness. Roman Catholics know that they are a part of something that always has been and always shall be. The Catholic Church is the very antithesis of the Church of What's Happening Now. It is unconcerned with marketing data, and therefore lacks the sense of crass commercialism and consumerism that pervades much of modern evangelicisim. If you look at a Catholic cathedral, you know that it'll be here a hundred years from now. If you look at a mall-like megachurch, you wonder if it'll be here when the current pastor leaves. One of the major appeals of Catholicism is its permanence and stability. In a world of rapid change, people crave stability. They yearn to know that they are a part of something that has a long history and a long future.