If you have hydractive suspension, you can raise the car up and support it with a jack or axle stand and gravity feed the kit into the tank. No need for a post lift, as gravity will do the job. If you have metal suspension the same applies, just raise the car at the rear and support that corner safely so that you can get to it.
As for mileage remaining:
The diagnostic tool interrogates the engine ECU on the following parameters :
- The quantity of additive deposited in the particle filter
- The quantity of additive remaining in the additive reservoir
The diagnostic tool (Lexia/ Diagbox) compares these values with the additive consumption stored in memory, the vehicle mileage and the distance remaining before the next servicing interval.
If the quantity of additive is estimated as
sufficient, refilling of additive does not need to be done; the diagnostic tool indicates: "Account taken of the vehicle history, it is not necessary to top up the level of additive in the reservoir. Check the level of additive again at the next servicing interval".
If the quantity of additive is estimated as
insufficient, refilling of additive is requested; the diagnostic tool indicates: "Taking account of the vehicle’s history, it is necessary to top up the level of additive in the reservoir".
So it depends on when the next scheduled service is as to if it determines there is enough additive to last until it would normally be checked, If not, the warning comes on at the dash, - so look at your miles remaining until next service. If is said you had 500 KMs remaining until your next service - it means the engine ECU has calculated there isn't enough additive remaining to cover you. If you had say 2000 KMs remaining until service it would mean you are probably likely to be able to go for a few more miles before limp mode kicks in than with 500 KMs remaining. It's not an exact science, but I would get it done sooner rather than later.