What speaker size is in the front of the GS with nak?

 

4" round, in a plastic enclosure.

 

so what kind of aftermarket speakers will fit in?

 

There are a few brands that make 4'" speakers, however some guys here have upgraded their speakers to 5.25 and 6.5 speakers, which makes a big difference.

 

Here's my write-up on the 6.5s I installed in the front doors of my 98 last year. If I were you, I would definitely consider building your own boards as opposed to cutting up the stock enclosure. I know that many people have carved out the stock enclosures to handle 5.25s, but the problem is that if you ever want to go back to stock (like to sell the car), you can't use those enclosures anymore. Anyway, hope this helps:

https://www.clublexus.com/forums/sho...y+speaker+swap