OP I feel for you but I'm not sure how you are going to find what you need. Don't forget that programmes like Supernanny are edited to look good and real life isn't usually like that.
My advice would be to take a step back and work out why she is behaving in this way. A wise person once told me that all behaviour is communication. So what is your DD trying to tell you?
I know you have only painted a tiny bit of the picture here but it looks awfully like she is fighting for your attention.
You wanted to think about the shopping and she wanted you to concentrate on her. As soon as she knew what would distract you she used it to get your attention.
In the cafe she can drag you away from your socialising by running off, thereby monopolising your attention.
If she refuses to get in her car seat a 5 second job in which she momentarily has your undivided attention becomes much longer.
In the evenings she chatters at you to ensure she is engaging your attention.
Her aim isn't to make you angry or unhappy. She is perhaps feeling the need for a little reassurance that she is still the centre of your world and always will be.
Try finding some ways to make your interaction with her a bit more positive.
If you know that you will have to give her attention while shopping to manage her behaviour, pre-empt it by giving her her own shopping list with pictures to tick off as you go round and offer praise each time she finds something. This changes the negative attention to positive.
When you put her in her car seat spend a few extra seconds giving her a kiss/tickle/stroke on the face and spend a moment talking about what you can both see or where you are going next. That way the nice part of the process is extended and she will look forward to it.
If you can't listen to a whole evening's chatter (I certainly struggle with this) make a special time when you sit down with her and give her your full attention. Ask her questions about her day or what is interesting to her at that point. After this time is over explain to her that you now need to do some jobs and thank her for sharing her thought/feelings/day with you. You may find that she doesn't always feel the need to talk at you once she has been listened to.
Lastly look constantly for opportunities to praise her and appreciate the good things she does. It can be very tiny things like hanging up her coat or stepping over a toy rather than walking on it. It doesn't matter what you choose to praise. The point is that, if you tell her what you like about her and what she does, you are giving her positive attention which will build her self-esteem and she should feel less driven to engage negative attention.
These things don't really take any more time than the behaviour management you are already doing but they do take a little more forethought and energy at first. Once you are in the habit of doing them it is much easier.
I hope that all makes sense. It is hard work to change your responses in this way but it is well worth it.