well if you are fast enough and Q2 lasts 15min you can do whatever you want in that time (but it needs to be during Qualifications time).
"34.2 Each car will be deemed to be in parc fermé from the time at which it leaves the pit lane for the first time during qualifying practice until the start of the race. Any car which fails to leave the pit lane during qualifying practice will be deemed to be in parc fermé at the end of Q1.
Between these times, other than when cars are returned to the parc fermé overnight, the following work may be carried out :
a) Engines may be started.
b) Fuel may be added or removed and a fuel breather fitted.
c) Wheels, wheel fasteners and tyres may be removed, changed or rebalanced and tyre pressures checked.
d) Spark plugs may be removed in order to carry out an internal engine inspection and cylinder compression checks.
e) Permitted heating or cooling devices may be fitted.
f) A jump battery may be connected and on board electrical units may be freely accessed via a physical connection to the car.
g) Charging and / or discharging of the KERS energy storage devices.
h) Removal of the KERS energy storage devices which, once marked by the FIA technical delegate, may be retained overnight by the team.
i) The main electrical battery and radio batteries may be changed.
j) The brake system may be bled.
k) Engine oil may be drained.
l) Compressed gases may be drained or added.
m) Fluids with a specific gravity less than 1.1 may be drained and/or replenished, however, fluids used for replenishment must conform to the same specification as the original fluid.
n) The aerodynamic set up of the front wing may be adjusted using the existing parts. No parts may be added, removed or replaced.
o) If the FIA technical delegate is satisfied that changes in climatic conditions necessitate alterations to the specification of a car, changes may be made to the air ducts around the front and rear brakes and radiator ducts. These changes may be made at any time after the message “CHANGE IN CLIMATIC CONDITIONS” is shown on the timing monitors, from this point the choice of air ducts around the front and rear brakes and radiator ducts is free and pitot tubes may be covered or uncovered, subject always to compliance with the relevant Technical Regulations.
p) Bodywork (excluding radiators) may be removed and/or cleaned.
q) Cosmetic changes may be made to the bodywork and tape may be added.
r) Any part of the car may be cleaned.
s) On board cameras, marshalling system components, timing transponders and any associated equipment may be removed, refitted or checked.
t) Any work required by the FIA technical delegate.
u) Changes to improve the driver's comfort. In this context anything other than the adjustment of mirrors, seat belts and pedals may only be carried out with the specific permission of the FIA technical delegate.
The addition or removal of padding (or similar material) is also permitted but may only be carried out under supervision and, if required by the FIA technical delegate, must be removed before the post-race weighing procedure.
v) Drinking fluid for the driver may be added at any time, however, the capacity of the container for any such fluid must not exceed 1.5 litres.
w) Repair of genuine accident damage.
x) Any parts which are removed from the car in order to carry out any work specifically permitted above, or any parts removed to carry out essential safety checks, must remain close to it and, at all times, be visible to the scrutineer assigned to the relevant car.
Furthermore, any parts removed from the car in order to carry out any such work must be refitted before the car leaves the pit lane.
Any work not listed above may only be undertaken with the approval of the FIA technical delegate following a written request from the team concerned. It must be clear that any replacement part a team wishes to fit is similar in mass, inertia and function to the original. Any parts removed will be retained by the FIA.
However, if a team wishes to change a part during the qualifying session and/or on the grid before the start of the race, this may be done without first seeking the permission of the technical delegate, provided it is reasonable for the relevant team to believe permission would be given if there was time to ask and the broken or damaged part remains in full view of the scrutineer assigned to the car at all times."