Have a car payoff question. and investment question.

All Vanguard. I am making full monthly Roth IRA contributions so it maxes out early. I opened a brokerage account last year and now I invest $1,250 month to it. Have 2.5% on our mortgage. No credit card debt. I bought a 2024 car, payment $550.00 at 4%. Owe $29,000. Brokerage Account (ETFs). Balance$33,749.52 Investment returns‡+$7,718.52 Rate of return††20% Question 1: I have an emergency fund of $50K in a money market. Should I use that to pay off the car or I was wondering if I should stop the $1,250 monthly brokerage contribution and use it to as an extra monthly car payment until its paid off? Question 2: Sometimes throughout the year I will have an extra $10K-$15K and I just let it sit. Would you recommend adding it to my Brokerage Account above? I thought about adding a CD but not sure. Thanks.