Multiple Regression
> lm_via_caret$results
  intercept      RMSE  Rsquared      MAE   RMSESD RsquaredSD    MAESD
1     FALSE 10.231392 0.8812081 8.531534 2.256155 0.06895833 1.930088
2      TRUE  6.569702 0.9554811 5.526304 1.438897 0.03747540 1.480363

> lm_via_caret$finalModel$tuneValue
  intercept
2      TRUE

> varImp(lm_via_caret)
lm variable importance
  Overall
c     100
b       0

> lm_via_caret$finalModel
Call:
lm(formula = .outcome ~ ., data = dat)
Coefficients:
(Intercept)            b            c  
    130.707        1.062       -1.383