BTW, us Stay at home moms don't have any help throughout the day either doing those things - our hubbies are gone to work, and even when they are home, it is mostly on us to keep the kids under controls/entertained/safe...at least in my experience!
Shower with her in there with you, two birds with one stone. Going potty - forget having privacy on that one - just let her come in and watch - it is good for her to learn about going to the toilet, and part of that is watching you. Shoot - put a little potty in there and have her "go" on it while you do, every little bit helps her learn.
As for starting the car, it depends on how far you have to go to the car -our garage is at the back of our yard....I would put on the TV to a kids show (mine don't watch much TV, so when I do turn it on , they are glued to it) and run out and start it and run back in. Mind you , our lower level is pretty much childproofed, and had gates, so she couldn't get upstairs on her own. If you saved up, maybe you could get an after-market remote-start installed on the car?
Taking stuff out of the oven, my girl learned very early that HOT hurts, she touched our fireplace insert, and got her fingertips burnt at 18 months, (even though there was a gate around it, she literally "broke into the gate" and we had warned her multiple times, she had to learn the hard way). But with hot, it usually only takes once. After that I would tell her HOT HOT - stay back, mommy is going to open the oven, and She would. With my second, he still hasn't learned that by experience, so I would repeat, and repeat it, and kind of block him with my butt, too, if he was getting too close/curious. Now we have a high up oven, over the stove, so they can't reach it - but they can still reach the burners, now that they are taller, so I still have to be very mindful in the kitchen - they know the kitchen is not for running or playing, and routinely get hollered at for coming in there while I cook - they are supposed to stay in the other room and play, as I cook.
You have to get creative, and you have to baby-proof your house, I put the child safety locks on all the lower kitchen cabinets and drawers,covers onthe doorknobs to the basement and stairs,and childproof locks on the entertainment center. We have gates at the bottom and top of both stairways, gate around the cornburner( fireplace insert - even when not using it), gate before the pantry that leads to the backdoor , lock on the front and back door that they can't unlock, all breakables and such are up high where they can't get them.
Good Luck!
Jessie