Ok thanks for the latter! FCC report have everything i needed 
So indeed, the US VCM is based on a cellular chipset Cinterion ALS3-US which is specialized in US frequencies and nothing else. There is another variant of that chip: ALS3-E, which is meant to support European frequencies and I suppose that the VCMs for European market are shipped with exactly that chip.
ALS3-US and ALS3-E specs also confirm there are no overlaps in terms of LTE frequencies but there is an overlap with some 2G(Edge) frequencies, so that explains why my car connects but with very slow datarate
Thanks for all the help and links guys! If anyone attemps to swap the ALS3-US chip with ALS-E successfully, please make sure to post it on the forum
So indeed, the US VCM is based on a cellular chipset Cinterion ALS3-US which is specialized in US frequencies and nothing else. There is another variant of that chip: ALS3-E, which is meant to support European frequencies and I suppose that the VCMs for European market are shipped with exactly that chip.
ALS3-US and ALS3-E specs also confirm there are no overlaps in terms of LTE frequencies but there is an overlap with some 2G(Edge) frequencies, so that explains why my car connects but with very slow datarate
Thanks for all the help and links guys! If anyone attemps to swap the ALS3-US chip with ALS-E successfully, please make sure to post it on the forum