library(ISLR)
auto_fit3 <- lm(mpg~(.-name)*(.-name), data = Auto)
summary(auto_fit3)
# acceleration:origin seems to be stat. significant in full model, let's
# check how the things are in model with only these two
auto_fit4 <- lm(mpg~acceleration*origin, data = Auto)
summary(auto_fit4)

Residuals:
    Min      1Q  Median      3Q     Max
-7.6303 -1.4481  0.0596  1.2739 11.1386

Coefficients:
                            Estimate Std. Error t value Pr(>|t|)
(Intercept)                3.548e+01  5.314e+01   0.668  0.50475
cylinders                  6.989e+00  8.248e+00   0.847  0.39738
displacement              -4.785e-01  1.894e-01  -2.527  0.01192 *
horsepower                 5.034e-01  3.470e-01   1.451  0.14769
weight                     4.133e-03  1.759e-02   0.235  0.81442
acceleration              -5.859e+00  2.174e+00  -2.696  0.00735 **
year                       6.974e-01  6.097e-01   1.144  0.25340
origin                    -2.090e+01  7.097e+00  -2.944  0.00345 **
cylinders:displacement    -3.383e-03  6.455e-03  -0.524  0.60051
cylinders:horsepower       1.161e-02  2.420e-02   0.480  0.63157
cylinders:weight           3.575e-04  8.955e-04   0.399  0.69000
cylinders:acceleration     2.779e-01  1.664e-01   1.670  0.09584 .
cylinders:year            -1.741e-01  9.714e-02  -1.793  0.07389 .
cylinders:origin           4.022e-01  4.926e-01   0.816  0.41482
displacement:horsepower   -8.491e-05  2.885e-04  -0.294  0.76867
displacement:weight        2.472e-05  1.470e-05   1.682  0.09342 .
displacement:acceleration -3.479e-03  3.342e-03  -1.041  0.29853
displacement:year          5.934e-03  2.391e-03   2.482  0.01352 *
displacement:origin        2.398e-02  1.947e-02   1.232  0.21875
horsepower:weight         -1.968e-05  2.924e-05  -0.673  0.50124
horsepower:acceleration   -7.213e-03  3.719e-03  -1.939  0.05325 .
horsepower:year           -5.838e-03  3.938e-03  -1.482  0.13916
horsepower:origin          2.233e-03  2.930e-02   0.076  0.93931
weight:acceleration        2.346e-04  2.289e-04   1.025  0.30596
weight:year               -2.245e-04  2.127e-04  -1.056  0.29182
weight:origin             -5.789e-04  1.591e-03  -0.364  0.71623
acceleration:year          5.562e-02  2.558e-02   2.174  0.03033 *
acceleration:origin        4.583e-01  1.567e-01   2.926  0.00365 **
year:origin                1.393e-01  7.399e-02   1.882  0.06062 .
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 2.695 on 363 degrees of freedom
Multiple R-squared:  0.8893,    Adjusted R-squared:  0.8808
F-statistic: 104.2 on 28 and 363 DF,  p-value: < 2.2e-16