Verguísimas is a highly informal and emphatic slang term derived from the word "verga" (which is vulgar slang for penis). The suffix "-ísimas" is an intensifier, similar to adding "very" or "super" to an adjective.
In the context of the song, when the artist says "Me veo verguísimas en la Merche'", he means he looks incredibly good or "f*cking awesome" in his Mercedes. It's a strong expression of confidence and swagger, common in certain urban music genres, and highlights the song's bold and boastful tone.
Get ready for some serious swagger with Michelle Maciel and Oscar Ortiz's "TRAIGO CON Q"! This song is all about living large and feeling yourself. Michelle Maciel kicks things off by saying he's gotten his revenge, flying high with lots of girls: "Me desquité / Con un chingo de morras me volé" [I got my revenge / I flew with a bunch of girls]. He even jokes about being asked for a three-way kiss and feeling too shy to say no!
He's got the look too, driving a Mercedes and wearing expensive Dior cologne: "Me veo verguísimas en la Merche' / Perfume Dior bien macizo me eché" [I look awesome in the Merche' / I put on some strong Dior perfume]. He's so confident that he doesn't even try hard; people just like him for existing: "Nomás por existir les gusto" [They like me just for existing]. He even says he was born handsome and a bit of a jerk, so the 'ugly ones' can do all the struggling: "Pa' eso nací guapo y mamón / Que batallen los feos" [For that I was born handsome and a jerk / Let the ugly ones struggle]. It's a fun, boastful track about having it all and knowing it!