Stretch bolts (NAC but LVWC)

[tihol_tiholov at sd27.bc.ca]

Hi all,
Any BTDT on a successfull replacement for stretch bolts and, if so, how do
you torque them.  Reason - it would be nice not to have to order bolts from
the dealer.
Example - in re-installing a right motor mount on a '99 Beetle 2.0
(LittleVWContent) there are 4 stretch bolts: 2 M12X1.5 about 90-100 mm long
and 2 (I think) M10X1.5 65 mm long.  Now the latter are replaced with 10.9
(instead of 8.8 steel) non-stretch type bolts and torqued to spec (30
ft-lb) without the additional 90 deg.  The former are temporarily re-used
and torqued to spec (44 ft-lb) without the additional 90 deg.  The specs
are per Bentley.  Any theory on stretch fasteners - better or not than
regular - is also welcome.

TIA

Greetings,
Tihol

P.S.: The car passed a test drive of about 40-50 km on tarmac.