Mother cannot stop lying to me - even about little things

Later this morning, as I was about to leave the house to go to the city, my mother asked me if I wanted to a lift into town because she was going there shortly. I acquiesced, telling her I would appreciate a lift so that I wouldn't have to wait for public transport.

Once in the car, she was just her usual antagonistic, bullish self.

I cant actually talk to her and get a straight answer from her, she always obfuscates, outright lies, evades or pretends she doesn't hear me. Or, she'll answer a completely different question, one I never even asked her! Totally frustrating to have a conversation with someone who doesn't listen to a word you say.

When we got close to the city, I asked her why she was going to the city and the conversation went like this:

Me: So what are you planning to do in the city today?
Mother: Nothing. Just walk around the place. I don't have anything to do here. I just felt like going to the city.
Me: So why are you going to the city when you are not doing anything here? (I am perplexed, as she never just "goes to the city to do nothing")
Mother: No reason, just because.

Then I notice her bag with her towels in the back of the car. She takes hew own towels to her masseuse because she wants to lie on and be covered by her own towels and not the ones used there. So then, the conversation goes like this:

Me: Why cant you just be honest with me and tell me you're going to the city to get a massage?

She proceeds to ignore me, pretending that she never heard me, because she doesn't want to admit she lied about such an inconsequential thing.  Oh, the frustration dealing with someone like her is immeasurable! She is simply unbelievable! She absolutely hates it when people lie to her, she suspects everyone of lying to her and yet, she doesn't stop lying even about minor things, not just to me, but to everyone. She has absolutely no self-awareness at all.
At that point, we reached the parking lot and I told her I was going and left the car and walked to the shops to complete some errands.