The first car to have a built-in GPS was the 1998 Lexus LS400 and up untill recently was still pretty rare, so this was groundbreaking technology when the song came out in 2002. Mannie Fresh is bragging about how he is rich enough to get all the newest features on his car.
1998 Lexus LS400:

Conscious rap, being such a critical art, requires a great deal of both awareness and education. Most of the factors supporting the racial caste system in America are blatantly exposed in American demographic statistics. Mos Def is telling us that you need to be equipped with adequate analytic skills (particularly mathematical ability) in order to effectively criticize the world around you. The genre is so diluted with sub-par artists and lyrics that essentially encourage complacency and discourage social action.

Leif Ericson was a Norwegian Viking regarded as the first European to land in North America (excluding Greenland), nearly 500 years before Christopher Columbus. We are still in the mind of a young boy, passionate about adventure and adventurers.

Young Noble is saying that he’s ready to put an end to any competition, specifically Nasty Nas. 2Pac (although this verse isn’t sung by him) dissed Nas on his song Against All Odds.

Extremely interesting fact: Nas cried when he heard the diss from Against All Odds(source). He is also a huge fan of 2Pac.

Note: 2Pac and Nas had allegedly met and squashed their beef shortly before Pac was murdered, but Pac was never able to edit out the numerous disses towards Nas because of his death.

Also could be referencing ‘Nasty New Street’, which is a street/hood in New Jersey that some of the Outlawz hail from, including Young Noble. They’ve made several references to this in other songs, for example, Kadafi in “All About You” says:

“I gets Down like Dru and my nasty new niggaz, too”