I've had 5 different cars in my life so far and 3 of them were lexuses. I keep going back because nobody else can build a better machine. I would keep your baby if I were you. Listen to what everyone else is saying... If you begin to mod, you will fall in love all over again.

for you gs4 guys...LSD and torque converter. and there you go...you got a whole new car

like everyone else has already said, I vote that you keep the Lex, mod her up a bit more, and use the extra money on something else (project car, vacation, your GF.....etc).