W4 withholding changes to break even

1. I hover in the 22% tax bracket with retirement income.  I'm withholding enough, I have not had a year yet where I have not had misc additional income (which I do have withholdings taken out). If I use the w4 tax calculator should I change my withholdings for 2024 -or- have "additional" withholding taken for this current tax year? 

 

2. I will have a small sum appx $23,000 from my deceased mothers estate. I will be issued to me but I will be splitting it amongst my 4 other siblings. Do I need to have the withholdings done prior to disbursement to me? 

 

3. I will need to purchase a vehicle this year. Does it make more sense to withdraw the funds from my IRA or do a car loan?