Residuals by predicted values
The plot of residuals by predicted values clearly shows the two most underperforming vehicles. Additionally, you can see that the Breeze, Prowler, SW, and Explorer are quite close to the majority of cases. This suggests that the apparent underperformance of the Breeze, Prowler, and SW and overperformance of the Explorer could be due to random chance. What is somewhat disturbing in this plot are the clusters of cases far to the left and to the right of the general cluster of cases. While the vehicles in these clusters do not have large residuals, their distance from the general cluster may have given these cases undue influence in determining the regression coefficients.

step  To check the residuals by price, from the menus choose:

Graphs
 Scatter...

step  Click Define.

step  Select Standardized Residual as the y variable and Zscore: Price in thousands as the x variable.

step  Select Model as the variable to label cases by.

step  Click OK.

The resulting scatterplot shows points far to the right of the others.

step  To identify the points, activate the graph by double-clicking on it.

step  Click the Point Identification tool.

step  Select the points.

The scatterplot reveals that the unusual points noted in the residuals by predicted values scatterplot are high-priced vehicles. The distribution of prices appears to be right-skewed, so you may want to use standardized log-transformed prices in future analyses.

step  To check the residuals by wheelbase, recall the Simple Scatterplot dialog box.

step  Deselect Zscore: Price in thousands as the x variable and select Zscore: Wheelbase as the x variable.

step  Click OK.

The resulting scatterplot shows points far to the right of the others.

step  To identify the points, activate the graph by double-clicking on it.

step  Click the Point Identification tool.

step  Select the points.

The points to the right of the general cluster in the plot correspond to points to the right of the general cluster in the residuals by predicted values scatterplot. As with the price distribution, you may want to use standardized log-transformed wheelbase in future analyses.