Stock 'radio' help...

[gullmercy]

So I'm installing a sound system in my car, i have all the parts necessary even a new deck except i found out the dashkit i will need to install my deck will cost me about 100$ from toyota its the 55405b model. I don't want to spend that much money and the current dash looks pretty sleek...however after installing just the speakers I realized that my deck only goes to level 50 volume and after that it just says max and doesn't go any louder. I was wondering if there is anyway i can change that so i can go as high as i want. I want to be able to do the same with bass, treb, etc...