Finished this little devil now. Boy - this thing is pure evil but sooo much fun! That pic shows how it drives...with the back out...a LOT
I put lead where the magnet once was...and two layers of lead on both sides ob the motor and behind the guide. I cut down the interieur drastically. Well after all it is gonna be a racecar...so we only need one drivers seat - not more. The remains were glued in. The driver now sits on the left side (sorry...I am used to driving on the left)
I slimmed down the chassis all around to help the body float, cut down the body-posts 1,5mm to get the body lower.
Before all that the chassis was 44g, now it weighs 63g
I finally sanded down the tires to 19,5mm diameter to get that thing even lower.
And to set it apart from the stock beetle I gave mine an orange stripe and painted the drivers helmet. Now the test drive: It lapped my track a whopping 1.6 seconds faster than in stock-form (without magnet) and thats with the stock-tires which are not that great really.. That is mostly because it no longer rolls at the mere sight of the curve anymore and follows the slot a lot better.
It still tumbles if you overdo it, but life is much easier now. Now I am waiting for a set of PU-rear tires to get the times even lower.