Really thinking hard on treading a 20 es with under 8K miles on her.
If I do so will the dealer allow me the swap out wheel's amp/sub box?

 

Swap out what for what?

 

Can i replace the stock wheels on the new ES with my custom wheels?

 

So you want to put brand new wheels and tires on your used car for the dealer? I think it's likely they'd love that!

 

Ok so your current car has mods that you want to put on your new car and give them your OLD car with brand new parts from the new car.

I guess you could ask. unless they see value in your aftermarket parts. some markets/neighborhoods like mods and dealers put those cars front and center. depends on the dealer and what they think will be best for them.