We just purchased a Whirlpool dishwasher. It doesn't have levelling legs at the back, but rather adjustable wheels. We still need to raise the dishwasher up a bit so the instructions say to shim it and secure the shims. What do you suggest for this? We used wooden shims and just taped them to the floor. Will this do the job? Also, when securing it the underside of the counter top, are you supposed to secure it to the front lip of the countertop, or push the dishwasher in further, and using a block of wood, secure it to the block of wood which is secured to the underside of the countertop?

Push DW in until flush with the cabinets (with door closed). Secure to underside of counter top with two screws through metal tabs. Shims taped or glued to floor should be fine.