take the plastic sill trim off and use this product i took this from my build, Its always better to do it before there is a problem.. i dont think starlets have a problem with the rear arches but i still posted to show the results...
I ordered two Dynax S50 its a high-performance anti-corrosion wax
http://www.bilthamber.com/dynaxs50.html
that provides exceptionally long-lasting protection to steel surfaces. It creeps into welded seams and seals surface defects. Dynax S50 forms a soft, brown, wax-like film that self-heals in the event of disruption. the total cost for the 2 x 700ml Cans is £ 28.85 to the door each can comes with a 60cm cavity injection lance thats can be attached for the hard to reach places
As the see the lance covers all round spray pattern
First pass i did the seam as this is where the car will rust first..
completed a finished
also did the both sills.
no bad for the price..