Do I have the Wrong battery?

I have a 2000 jaguar s-type 3.0, when I got the car the guy said the stereo and the battery and other lights will go on and off when I’m driving and it does, he said it’s because it’s not the battery that came with the car. Is that true on why it does this ?

I’m not really clear about the question you are asking. In the UK the correct battery fitment is an 019, 100AH.
I don’t know what you mean by the stereo light and when you say battery light do you mean the generator warning light? If that is true, the battery may not be being charged and a low battery can give all kinds of spurious fault indications.

So that’s the exact battery for a 2000 jaguar S-Type 3.0 L?

I don’t know where you are but if in the UK, an 019 is correct. I put a Varta H3 (600 402 083) in mine.

I’m in a Hayward Wisconsin in the US

Here’s what’s in mine. Autocraft H8-AGM with 900 cold cranking amps at 0F. My previous one was Autocraft 94RH7 with 765 cold cranking amps at 0F.
You’re in Hayward and its January. Brrrr. You might want to run down to your local auto parts store and get them to check your battery.

Yeah I heard the “gold” batteries would work for my car as well, the platinum one would work to?

Yes, my previous one was a gold. More cold cranking amps is better. It all depends on how deep is your pocket.