seems price on the frpp aluminum driveshaft have gone up, i remember them being around the $150 range. You can put them on an auto just have to re-use the yoke from the stock driveshaft.
after cleaning the engine with degreaser, you can use engine dressing like CD-2 to give it a shiny look if you want
Amazon.com: CD-2 Engine Detailer 12.5 oz.: Automotive
im sure you can rent a car at the age of 24..they will just add a age restriction fee. I was able to rent a car in orlando when I was 21 but they added a fee for 21-24 year old drivers.