  In this note we prove that the moduli stack of vector bundles on a curve,
with a fixed determinant is $\mathbb{A}^1$-connected. We obtain this result by
classifying vector bundles on a curve upto $\mathbb{A}^1$-concordance.
Consequently we classify$\mathbb{P}^n$- bundles on a curve upto
$\mathbb{A}^1$-weak equivalence, extending a result of Asok-Morel. We also give
an explicit example of a variety which is $\mathbb{A}^1$-h-cobordant to a
projective bundle over $\mathbb{P}^2$ but does not have the structure of a
projective bundle over $\mathbb{P}^2$, thus answering a question of
Asok-Kebekus-Wendt
