A few in our group have used Westin's spa for massages over the years and liked the services. I'd recommend booking as soon as you know the day/time you want if you are limited on time frame with the wedding going on. Plus if you want female/male masseur.
There is also a 'spa to go' company that will come to you for makeup, hair and possibly massages. http://www.spatogo.ky/
And for hair and nails, the girls in our group have used the services at the salon located at The Strand shopping center(where grocery store Fosters is located). http://spaesprit.com/
We use Avis at Westin for car rental routinely but early in our trips(staying central SMB) utilized companies that would pick up the driver at your hotel/condo, drive you to their SMB location at which time you would get your vehicle then be on your way. So no worry about not being able to check the vehicle. Then for return, drop the car to them and either they'd bring the driver back to hotel/condo or they'd walk depending on distance. Best to verify that type of service is offered if it's important.
Edited: 11:53 am, June 26, 2013