undercoating or electric box

[canadiangator]

bought a used 3 its a 07 its never been undercoated, there is rust starting on the top of the suspension in the engine bay should I buy one of those electronic gismo's or go get the car undercoated?

witch do you prefer and why? pro's and cons?

[yearoftherat]

Search is your friend:

http://http://www.torontomazda3.ca/forum/showthread.php?t=14275&highlight=electronic+rust