Can anyone please suggest how I can extract the coefficient of my explanatory variable after using the Bayes command? Example below

Code:
sysuse auto, clear
bayesmh foreign trunk mpg, likelihood(logit) prior({foreign:}, normal(0,1000))

mat list e(mean)
result of mat list
Code:
e(mean)[1,3]
trunk    mpg    _cons
Mean  -.13484497    .11758344    -1.7574044
I want to extract mean of trunk and mpg only in a postfile but not sure how to define the matrix for each of the explanatory variables.

My try shows an error message:
Code:
postfile examp trunk using "bay.dta", replace
bayesmh foreign trunk mpg, likelihood(logit) prior({foreign:}, normal(0,1000))
post examp (e(mean))
postclose examp
type mismatch
post: above message corresponds to expression 1, variable means
r(109);

any suggestion is appreciated