Unless you made the ES 300 a rear wheel drive car and did some major modifications, you WILL NOT be able to fit any Toyota/Lexus 3L I6 engine in the car (I6 is too long). Hence why the ES has the V6.

I like the previous ES 300 to the current model out. They seem to have more umph than the current ones.

As far as performance mods, I don't know of any .