Did you not read the rest?
I did, nowhere do you mention 8 car headlight bulbs.
I do not understand why you say PWM would not work, it would.
A reply can only be as good as a question, and missing out vital information or not making things clear results in people asking you supplemental questions. Your original question was confusing because you said 0-5V from the arduino. The arduino only produces 0 or 5V nothing inbetween.
If you take my replies as offensive then I will not bother trying to help you anymore.
First, i didn’t think the 8 bulbs was relevant. I was asking for the electronics equivalent of an analog amplifier. Secondly you ask me about range which i clearly stated. I’m new on this stuff and that’s why i come to forums like this. Now i feel that my head gets bitten off for not asking the right questions.
Back to the topic: How would PWM work? I was thinking like something of a digital trimpot, but clearly i am misinformed. I thought there was something like analogWrite…