A friend has spoken to me about investing in rhodium as it has the "potential" to reach its once epic heights... After doing some research and seeing the trend of its price, am I wrong to think that it's sudden increase over the 07/08 period was more of a manipulation (by investment firms?) instead of an actual change in supply/demand by the automotive industry
Any input would be great as I don't really have a background in economics

Commodities trading for individual investors is a fools game you are far more likely to lose than win at.

You are better served investing in S&P 500 index funds.