In general there are cars that are always on top for resale and others that are always on the bottom. The Honda Accord, although not at all difficult to find and buy, remains consistently on top, whereas the Ford Tarus, Kia, Hyundai, and Buick are consistantly at the bottom.
There are other factors related to supply that influence prices. A few years back the Ford F150 took a dive and the lease rates were horrible. This was due to a big upcoming surge of lease maturities and the expectation that a market flood would push down prices.
BWM is in the same boat now. My car is $170.00 more per month for the same lease terms than I paid one year ago. A very small portion is due to interest and the rest is adjusted residual because the expectation is for a market drop in resale value.
So yes, there are a lot of factors that influence resale. But at the same time there are some time-tested factors that still influence the value a great deal, and consistently, over the long term.