Can't say I'd be asking for investment advice on a forum that is dominated by people 18-22
Assuming you want to be conservative, I'd say a CD or money market is the way to go. Could purchase a bond and sell it a year from now, but the returns could be minimal, or you could lose out if rates change for the worse from the yield your note has. If you have 20k to invest, I highly doubt you want the opinion of people on a car forum though
