When you say full sun & shade does this mean it gets morning full sun and afternoon shade or morning shade and afternoon full sun. This can make a difference because generally morning sun is gentler and afternoon sun is stronger. In the corner, but the wall, I would plant a skinnier, slowgrowing evergreen to add height and interest. Around the mailbox, grow a vine such as clematis - pick one that blooms all season. Some clematis only bloom in the spring. You could edge the front with a variagated lirope. It looks kind of like a pretty grass but it does have purple flower spikes too. In between the lirope and the evergreen (dwarf alberta spruce comes to mind as a suggestion) you could plant a medium height plant. Pick a color scheme and plant accordingly. Black eyed susans or stella d'oro if you want yellow, veronicas, catmint, or purple coneflowers for blue/purple, shasta daisies for white, guara, strawberry candy daylily or geranium "rozanne" (the perennial kind of geranium) for pinks/reds/violet. You could subsitute flowers for interesting & colorful leaves with Heucheras that have reddish/purple tints or hostas with white/green/yellow and/or blue colorings. Only plant heucheras and hostas if you have morning sun in this patch. Afternoon sun will bleach the leaves. Hope this gives some ideas. I picked fairly common plants that you should be able to easily find at a nursery that have a long season of interest. You may see something else that strikes your eye when you go shopping.

It's stink bug nymph (youngster).

Close Up Picture

Actually "I" havent assumed anything, I am simply giving you a perspective that you don't presently have, at least you didn't have when you first posted. As far as "the leak" you have not told us if it is engine coolant, or simply water. The photo appears to be the tubes for the heater core which are not normally visible so easily. Now comes the hard part. Unless the Kia dealership has a former Saturn technician on staff, then they really don't have any first hand information about your car at all. It's quite possible that one of the line technicians never even saw your car at all if it didn't present any symptoms which would have gotten anyones attention. The wetness in the photo can be condensation from the water evaporating and then condensing back to a liquid when it contacts the plenum, or the leak could be from above that area. Investigation will be required. It's quite likely this may even get sublet back to a Saturn dealership by the Kia one. You say in your last post that you want to make sure the problem is solved and communication to that extent is what is important. I agree fully. That's why the first step is to make sure you don't go in with false assumptions. Stick to the facts, and the symptoms you have found. Then let them do their job.