Is Hijazi dialect confined to Mecca and Jeddah alone? I lived in a place which was part of the Mecca area and they used to say that.
What part of the Mecca area did you live in? The Saudi province of Mecca today includes a chunk of Najd, by the way.
Traditionally, there were two groups of dialects in the Hejaz.
There is the speech of the large cities (Jeddah, Mecca, Medina, Yanbu, and some inhabitants of Al-Taif), which is usually referred to as "Urban Hejazi." This is a dialect that shares a lot in common with urban dialects outside the Peninsula, especially Egypt and the Sudan but also Syria, etc., including a lot of Ottoman influences. Of course it also has many Arabian features as well.
Then there is the speech of the tribes of Hejaz, who used to live outside of these cities, or in separate communities in these cities. People sometimes call this "bedouin Hejazi," even though many of its speakers are not bedouins per se but simply belong to tribal groups. This is a typical "bedouin-type" dialect that sounds a lot like the dialects of central and southwestern Arabia.
Now, in modern times, things have become more complicated because most of these tribes have become urbanized and have moved to the cities like Jeddah and Mecca. Plus those cities have received a lot of immigration from other parts of the country, especially from the south. the two dialect groups I described are influencing each other and assimilating each other's features to varying degrees depending on the speaker. There are of course still many people who speak more or less "pure" urban Hejazi or (to a lesser degree) "pure" bedouin Hejazi, but there are increasinbly a lot of people in Jeddah and Mecca who fall somewhere in between those two ideals, though I think the pull of the urban type is much stronger.